Automatic Air Valves For raw and potable water For domestic and industrial sewage Technical information for project planners and technicians
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Table of contents 1. The purpose of aerating and air release 4 2. The points of aerating and air release 4 3. The ways of aerating and air release 5 3.1 Ways of functioning 5 3.1.1 Functioning of H-TEC air valve Model 987 (here type 2 ): 5 3.1.2 Functioning of H-TEC air valve Model 986: 5 4. Types of air valves 6 4.1 AV Model 987 - Air valve (single orifice / double orifice) 6 4.2 AV Model 986 - Air valve (with cup seal) 6 4.3 AVS Model 992 and Model 985 Air valve set 7 4.3.1 Description of AVS Model 992 Description of AVS Model 985 (diaphragm) 7 4.3.2 Installation above and below ground 7 4.4 Accessories 8 4.4.1 Surface box for below ground installation of air valve set Model 992 8 4.4.2 Drainage element for air valve set Model 992 8 4.4.3 Manhole cover and ring for air valve set Model 985 8 4.4.4 Indicator plates for air valve 8 4.4.5 Flushing and water tapping set (for air valve set Model 992) 8 5. Rating of valve size 9 5.1 Rating of valve size 9 5.2 Rating according to the flow performance diagram 10 6. Installation 11 6.1 Design of the connection 11 6.2 Air valves in plants and manholes 11 6.3 H-TEC air valve set, the logical further development of the air valve 12 6.4 Shortening of air valve set Model 992 on site 12 6.5 AVS - installation in existing manholes 12 6.6 AVS - installation in ground water 12 6.7 AVS - installation in flood areas 13 6.8 AVS for waste water in ground water areas 13 6.9 AV for water treatment plants 13 6.10 AV for sterilization plants 13 6.11 AV upstream and AV downstream of control valves 13 6.12 AV in fire extinguishing systems 14 6.13 AV upstream and downstream of reductions 14 6.14 AV on waste water head pipes with automatic aeration 14 6.15 AV on waste water vacuum pipes 14 6.16 Insulation 14 7. Pressure testing 15 8. Functional testing and maintenance 15 8.1 Reasons for maintenance 15 8.2 Maintenance intervals 15 8.3 Important maintenance work 15 8.3.1 Maintenance of air valve set Model 992 16 8.3.2 Maintenance of AVS Model 985 17 9. Specification 18 9.1 Air valves 18 9.2 Air valve sets 19 9.3 Air valve with stand pipe base 19 9.4 Accessories 20 10. Safety hints 20 11. References 20 Page 3
1. The purpose of aerating and air release A water transport system is to be kept in an operating condition as stable as possible by taking the appropriate measures. Inclusions of air may have considerable negative effects on a pipeline system, such as: - longer running time pumps - higher energy input, shorter lifecycle of pumps - pressure fluctuations - reduction of flow - water hammer - pipe breakage - dry running of pumps The possibility of air entering into a pipeline system cannot be eliminated entirely. Already the air dissolved in the water proper may turn gaseous under certain pressure and temperature conditions. Even larger quantities of air will get into the pipeline system during maintenance work. These amounts of air will collect at certain points from where they have to be carried off by means of the appropriate valves (see below illustration). On the other hand, the lack of air may also lead to failures. Negative pressure will be created when water flows off too fast. This is mostly the case when pipes get drained or when pipe fractures occur, as well as in case of pumps being disconnected or downstream of quick-acting valves such as pipe fracture safety valves, where the flow of water is stopped abruptly, thus creating a negative pressure between the valve and the head of water being discharged. In this case sufficient air must be admitted to the pipeline through the air valve to limit the negative pressure and prevent damage to the pipeline. Moreover, there are accumulations of gas in waste water because of processes of decay and because of the deliberate blowing in of air. This implies the following requirements on air valves: - releasing minor amounts of air under operating pressure - releasing major amounts of air - admitting major amounts of air 2. The points of aerating and air release b RBS e a b c d c c a b The Air Valve Releases air from the pipeline: accumulations of air must be expected where the operating pressure is lower than in neighbouring pipeline sections: a) at each geodesic high point b) at each hydraulic high point c) at long ascending or descending pipe sections (recommended installation in intervals of approx. 0.5 mile/800 m) d) downstream of pumps and upstream of throttling points The Air Valve admits the required amount of air: at each spot of the pipeline where negative pressure must be expected, such as: e) downstream of quick-acting valves (pipe fracture safety valves PFSV) 4
3. The ways of aerating and air release 3.1 Ways of functioning 3.1.1 Functioning of H-TEC air valve Model 987 (here type 2 ): Medium: potable water large cross section A = 1.488 in 2 small cross section A = 0.003 in 2 Releasing major amounts of air: During filling a pipeline releasing is effected via the large cross section. Releasing minor amounts of air: During operation of a pipeline releasing is effected via the small cross section. Aerating: During draining of a pipeline aeration is effected via the large cross section. Closing: After venting the valve closes automatically. 3.1.2 Functioning of H-TEC air valve Model 986: (This valve is also installed in air valve set Model 985) Medium: potable water and waste water A = 0.744 in 2 A = 0... 0.744 in 2 Releasing major amounts of air: For filling a pipeline the whole venting cross section is available. Releasing minor amounts of air: During operation of a pipeline the venting cross section will be opened as far as necessary. Aerating: During draining of a pipeline aeration is effected via the whole aeration cross section. Closing: After venting the valve closes automatically. 5
Ventilation on highest level for water pipelines Improved air intake and release capacity Very high air release during operation continuously variable from 0 to 250 psi / 16 bar High-grade materials Easy maintenance Excellent UV resistance Only for air release or air intake - on request 350 psi / PN 25 - on request HaVent, the new performance generation Air release capacity during pipeline filling The air release capacity is 106.000 gal/h even at a differential pressure of 1.45 psi / 0,1 bar Air release during operation The air release capacity over 26.500 gal/h even at a differential pressure of 29 psi / 2 bar Air release capacity Q (m 3 /h) Air release capacity Q (m 3 /h) Differential pressure (bar) Differential pressure (bar) Aeration of pipeline The air intake capacity is approx. 79.500 gal/h at a negative pressure of -1.45 psi / -0,1 bar Air intake capacity (m 3 /h) Negative pressure (bar) Possible connections Female thread 2 Male thread 2 Flange 4 Flange other nominal width on request! 6
Technical features Large outlet cross section for maximum air release and intake capacity during pipeline filling or draining A = 2.3 in2 Large air release cross section for reliable air release during operation Amax. = 0.3 in2 High-grade enclosure of aluminium Robust float of foamed plastics Flow control for optimized closing Valve mechanism No loose components Can be taken out in one piece Easy cleaning Easy exchange of wear parts if required 7
4. Types of Air Valves 4.1 Model 987 - Air Valve (single orifice / double orifice) Technical data: NP 2 NP 1 Test pressure (body) body 350 psi / 24 bar body 350 psi / 24 bar Operating pressure standard: 14.5-250 psi / 0,8-17.2 bar standard: 11.6-250 psi alternative: 1.5-87 psi alternative: 1.5-87 psi Opening cross section 1.448 in 2 / 0.003 in 2 0.003 in 2 Max. air release capacity 50.190 gal/h 2.377 gal/h Connection female thread 2 or flange female thread 1 Insect protective grid yes no Weight 5.1 lbs / 2,35 kg 1.65 lbs / 0.75 kg Materials: Body POM Seat CuZn35Pb3As Float POM Valve gasket EPDM UV cap PE Insect protective grid ss316 NPT 2 : for large amounts of air NPT 1 : for small amounts of air On request: valve with ventilate-function only 4.2 Model 986 - Air Valve (with cup seal) Technical data: Test pressure (body) body 350 psi / 24 bar Operating range 0-250 psi / 0 16 bar Opening cross section 0.75 in 2 / 480 mm 2 Max. air release capacity 230 m 3 /h / 60.760 gal/h Connection female thread 2 or Flange 2-8 Media other flanges on request raw and potable water domestic and industrial waste water Features: infinitely variable operation from 0 bar onward seat not in contact with the medium suitable for parallel operation large orifice = prevents contamination = high air release capacity even under operating pressure Materials: Body fluidized bed epoxy powder coated alternatively SS 316 Body nut with screen POM / 1.4301 Float Valve body - bonnet O-ring 160 x 6 POM POM NBR Outlet elbow with strainer PE 100 / SS 316 Large amounts of air can be released under operating pressure due to infinitely variable operation! 8
4.3 Model 992 and Model 985 Air Valve Set 4.3.1 Description of Air Valve Set, Model 992 Medium: potable water Description of Air Valve Set Model 985 (diaphragm) Medium: potable water and waste water hood with air vent slots additional elongated holes permit shortening by 100 mm stand pipe of stainless steel replaces the chamber and permits easy maintenance of the air valve cover chamber cylinder air valve insect protective grid operating rod H-TEC 2 air valve high-grade materials such as POM for the body, bronze for the seats and EPDM for sealings ensure corrosion resistance and permanent function (maintenance see item 6.) automatic shut-off function via initial spring tension ensures sealing even at 0 psi drain-off fitting shut-off facility with blank of stainless steel drain-off fitting (optional: can be closed via end fitting) BAIO spigot end 3 or flange 3 Both Air Valve Sets are available with flange 3 or BAIO spigot end. When using a BAIO spigot end please apply a dirt cover and locking ring (see specification of accessories). 4.3.2 Installation above and below ground An Air Valve Set can be installed both above ground and below ground. The above ground type will be used wherever the valve shall be installed in open terrain. Pipe cover depth: above ground below ground Above ground (PCD) 2.5 ft / 0,75 m 3.3 ft / 1,00 m 4.1 ft / 1,25 m 4.9 ft / 1,50 m Below ground (PCD) 3.3 ft / 1,00 m 4.1 ft / 1,25 m 4.9 ft / 1,50 m 5.7 ft / 1,75 m L Flange 2.5 ft / 755 mm 3,5 ft / 1055 mm 4.3 ft / 1305 mm 5.1 ft / 1555 mm L Spigot end 2.7 ft / 815 mm 3.7 ft / 1115 mm 4.5 ft / 1365 mm 5.3 ft / 1615 mm 9
5. Rating of valve size 5.1 Rating of valve size In general, there are no limits to the pipeline diameter for operational air release. However, the accumulating amounts of air of a pipeline must be considered. They must not exceed the values specified in the flow diagram. As regards the required valve sizes and/or the free flow cross sections thereof the diagrams and calculations are based on the following assumptions: a) Release during filling of a pipeline: - The maximum water hammer during closing of the Air Valve is limited to 44psi/3 bar (which is equivalent to a max. flow rate of 10 inch/s in the pipeline) - The propagation rate of the pressure surges in the pipeline is assumed to be a = 4000 ft/s - The maximum flow rate in the free flow cross section of the Air Valve is limited to V E = 65 ft/s, since an excessive flow rate of the air might tear along the float of the Air Valve, thus closing the valve before the venting process proper. b) Aeration during drainage of a pipeline: - The absolute pressure in the pipeline is limited: p R = 13.8 psi/0,95 bar (= negative pressure of 0.7 psi 0,05 bar) - The contraction and friction value of the Air Valve is: µ = 0,52 Diagram 1: Filling the pipeline Diagram 2: Draining the pipeline required venting cross section A [ mm 2 ] 100 200 300 400 600 900 2000 10 0 inside diameter di of pipeline di [ mm ] 200 300 400 500 2 4 6 10 14 18 40 max. adm. flow in the pipeline Q [ l / s ] Example of rating an Air Valve: For a pipeline with an inside diameter of d i = 12 the required size of the Air Valve shall be determined. Filling the pipeline: According to diagram 1 the free flow cross section in the air valve of a pipeline of d i = 12 must be at least 0.14 sq.inch. The flow in the pipeline must not exceed 4.8 gal/s. Draining the pipeline: According to diagram 2 the max. admissible flow on drainage of the pipeline is 11 gal/s at a free flow cross section in the valve of 0.14 sq.inch. This means that the H-TEC Air Valve Model 987 2 (A = 960 mm 2 ) is able to manage the accumulating amount of air for aerating and/or draining of a pipeline do 12 under the specified assumptions. Since the above calculation may not be perfectly adapted to any pipe pressure situation possibly prevailing we recommend a comprehensive hydraulic calculation*. If, during filling of a pipelines, even larger amounts of air 10
must be expected, air release may also be performed manually. In this case a flushing and water tapping set is installed in the H-TEC Air Valve Set. However, other air release devices such as hydrants, may be used, too. 5.2 Rating according to the flow performance diagram The following diagram shows the interrelation between air release and aeration capacity of the valve at a given overpressure / negative pressure in the valve. Explanation by way of examples: a) Air release capacity of AV 1 at 73 psi / 5 bar: 1.590 gal/h b) Air release capacity of AV 987 2 at 0.7 psi / 0,05 bar: 47.500 gal/h c) Air release capacity of AV 987 2 at 73 psi / 5 bar: 2.000 gal/h (as the big orifice is closed because of the air flow) d) Air intake capacity of AV 987 2 : 145.300 gal/h 11
6. Installation The points of installation are usually the relative or absolute high points of the pipeline. Because of the regular checks that are necessary they shall be easily accessible and not be situated in highly frequented traffic areas. However, the correct place of installation is more important (e.g. high point). 6.1 Design of the connection The nominal width of the supply line shall be as large as possible and should be equivalent to at least the valve size. This pipeline should run vertical from the pipeline to the valve. The dimension of the upstream shut-off valve, too, should be equivalent to at least the valve size. The largely dimensioned supply line to the valve serves the purpose of collecting the air carried along with the water from the main line at this point to be then discharged by the valve. For pipelines < 24 a sufficiently dimensioned ventilation chamber is required. Unless determined more precisely the ventilation chamber can be regarded as sufficiently dimensioned if its constructional height is equivalent to the diameter of the pipeline and its cross section is approximately half the cross section of the pipeline. Moreover, a central shut-off facility, a tee with air release and air intake facility and a lateral outlet for manual air intake and release as well as for depressurization before working at the air valve are required. The shut-off valve permits the installation and dismantling of the air release and intake facility as well as the manual air release facility without interruption of operation. Functional testing of the air intake and release facility and/or the floats and the manual air release facility with closed shut-off valve are possible. This shut-off valve must remain closed during pressure testing (see page 15). 1 2 3 air valve manual air release facility shut-off facility 1 2 3 Warning: Prior to installation of an Air Valve the pipeline must be flushed, since dirt and drilling chips might affect tightness (see also flushing and water tapping set). 6.2 Air Valves in plants and manholes Air Valves are installed in rooms or manholes. Inside the buildings care must be taken that the opening is sufficiently large to ensure an unobstructed flowing in and out of the air. By means of the integrated fine screen vermin and dirt are prevented from getting into the valve. As regards the design of the building care shall be taken that the residual water carried along in the process of air release can be discharged via a drainage device (drainage element). Warning: Prior to entering manholes make sure that sufficient fresh air is admitted! 12
6.3 H-TEC Air Valve Set, the logical further development of the air valve Advantages of H-TEC air valve set: low costs no access of manhole required integrated shut-off element maintenance work easy and time-saving No danger because of access to manhole! Conventional manhole H-TEC Air Valve Set 6.4 Shortening of Air Valve Set Model. 992 on site Both the above ground and the below ground version of the Air Valve Set may require shortening on site because of unexpected changes of the pipe cover depth. According to the drawing the operating tube (with the marking) and the stand pipe of stainless steel are cut by 4. Make sure to produce a straight cut edge. 6.5 Installation in existing manholes Air Valve Sets can also be installed in existing manholes. They are mounted on the pipeline instead of the old air valve. The manhole is backfilled with bulk material, thus avoiding future maintenance of the manhole. Moreover, the valve can be installed and dismantled from above for testing and maintenance. bulk material 13
6.6 Installation in ground water If rising ground water exceeds the level of the drainoff fitting dirty water may be sucked into the pipeline during aeration. The drain-off fitting must be closed or a back flow preventer must be installed. (This is not included in the standard scope of supply and must be ordered separately). In both cases it must be ensured by regular inspection of the Air Valve Set that no groundor rain water can accumulate in the Air Valve Set. If required,the water must be pumped out by means of a handpump. Warning: Penetrating ground or rain water may be sucked into the pipeline in case of negative pressure. Contamination and germs may be carried in. 6.7 Installation in flood areas In flood areas the length of the AVS shall be rated such that the hood with the air vent slots is approx 1.5 ft above the water level to be expected to prevent any dirty water from penetrating the Air Valve Set. The drain-off fitting must be closed. (This is not included in the standard scope of supply and must be prepared on site). Warning: Penetrating ground or rain water may be sucked into the pipeline in case of negative pressure. Contamination and germs may be carried in. 6.8 For waste water in ground water areas The drain-off fitting must be closed, e.g. by means of a pipe and end fitting, to prevent waste water from emerging into the soil. 14
6.9 For water treatment plants Automatic air release at the surge tank after water treatment with compressed air. For dimensioning, please consider the maximum air release amount at the given operating pressure of the Air Valve (see diagram). Because of its high air release capacity under operating pressure the valve Model 986 is best suited for this application. surge tank ARV compressed air from compressor 6.10 For sterilization plants In water sterilization plants the water is exposed to UV light. In this process air is set free that must be released at the highest point of the radiation plant. radiation cylinder ARV 6.11 Upstream and Air Valve downstream of controlvalves Control valves are very sensitive to airlocks in water. Therefore, depending on the operational conditions, it may be necessary to install an air release valve upstream of the control valve to ensure smooth operation. In this case a mere air release valve is recommended that is created by installing a nonreturn valve into the output pipe of the Air Valve (please order separa-tely). Warning: This nonreturn valve will reduce air release capacity! As at all throttle points in the pipeline system, air is set free downstream of control valves. Ideally, this air shall be removed from the pipeline while still in the manhole or building where the control valve is installed. Especially downstream of pipe fracture safety valves an aeration facility must be installed to prevent negative pressure as well as consequential damage to the pipelines caused by such negative pressure. 6.12 In fire extinguishing systems In fire extinguishing systems pumps are used that ensure sufficient delivery in case of emergency. These pumps will drag air into the pipeline that has to be removed again at the nearest high point. Before installation, please observe the applicable national regulations. 15
6.13 Upstream and downstream of reductions a) Upstream of reductions in the pipeline system, i.e. upstream of major contractions, air will accumulate that is not carried on (see curves for self-venting of pipelines. The Air Valve releases the accumulated air automatically. b) In case of flow from the smaller to the larger pipeline, too, venting may be necessary, e.g. for a descending pipeline, if the rate for self-venting is not reached. 6.14 On waste water head pipes with automatic aeration In some situations it is necessary to blow air into the pressure line via a compressor or pressure tank at regular intervals, in addition to normal pumping. In these cases we recommend the use of an air release stop, which is mounted at delivery (also possible later when already installed) on the valve outlet elbow. During normal pumping the air release stop is out of action. If, however, very high air quantities are supplied to the pressure line via a compressor or pressure tank,then the air release stop responds mechanically and closes the valve. After scavenging (air), the valve goes back to its normal operating state. For more detailed information please contact our applications engineering department. 6.15 On waste water vacuum pipes In waste water vacuum pipes only air release valves may be used. To this end a nonreturn valve shall be in stalled at the valve outlet side. Warning: This nonreturn valve will reduce air release capacity! 6.16 Insulation Valves installed directly on the main line are not very susceptible to freezing, since the water in the valve is heated by the water flowing in the main line. However, in case that an offset installation is necessary, i.e. in case of installation beside the main line, there is the danger of freezing. In this case both the supply line to the valve and the valve proper must be insulated. The valve in the Air Valve Set is protected from frost by inserting a disk cut to size and consisting of insulating material of approx. 2 in thickness with a hole in the centre (see drawing) is inserted halfway up the stand pipe. This disk must not seal tightly to ensure that air release and intake are not inhibited (approx. 10 holes with a diameter of 0.4 inch). The Air Valve in the manhole is protected from frost by lining the manhole walls and the manhole cover with insulating material (see drawing b). In case of waste water valves, too, insulation may be sensible. Though there is usually no danger of freezing, the depositing of grease at the wall of the Air Valve will be increased by temperature differences. 16
Drawing a Drawing b ø approx. 10 mm insulation insulation Air Valves installed in the open, for example below bridges, must also be insulated to be frost-resistant. In this case, insulation may be effected, for example, by backfilling the surface box with polystyrene chips. To discharge splash water a drainage pipe leading from the Air Valve into the open must be installed. 7. Pressure testing Prior to delivery H-TEC air valves are tested, including functional testing at max. operating pressure and body testing at 1,5 times the operating pressure. Prior to pressure testing of pipelines with Air Valve Set and/or Air Valve Sets the shut-off device must be closed, otherwise the pipeline may be vented during the pressure test, rendering the result of the pressure test useless. AV: AVS 992: AVS 985: Close shut-off device upstream of the valve. Take Air Valve out of the Air Valve Set the integrated shut-off device of the set closes automatically. Close shut-off device by means of half turn. 17
8. Functional testing and maintenance 8.1 Reasons for maintenance Almost all potable waters and waste waters carry along suspended particles and tend to sedimentation. In waste water there are also grease deposits and larger foreign bodies accumulating in the Air Valve. To avoid malfunctions caused by dirt Air Valves must be checked and maintained, if necessary, at regular intervals. 8.2 Maintenance intervals H-TEC recommends regular checks of Air Valves for potable water are demanded at least every 12 months. The exact maintenance interval depends on the quality of the water. The first maintenance will be done after 3 to 6 months after start-up and serves as a first reference value for further testing intervals. In case of waste water the maintenance intervals must be adapted to the conditions of the pipeline. Usually, the first Air Valves of a series of several valves are contaminated most heavily. There are no generally applicable rules for maintenance intervals. 8.3 Important maintenance work This information leaflet can show only the most important steps of maintenance. Please follow our maintenance instructions and comply with the safety hints. Prior to working at air valves the valve must be shut off via gate valve and unpressurized via an appropriate valve. Air valves represent one of the few automatic connections between the pipeline system and the ambience. Therefore, they have to be checked at regular intervals. (see also [2]). 8.3.1 Maintenance of Air Valve Set Model 992 a b c Pull out valve by means of operating tube Simultaneously the foot valve closes the system at the bottom Open surface box Loosen screw a Take off hood Loosen screw b Take out spindle support c 0 Maintenance of Air Valve 2 : - Clean body and seats - Blow out valve bore by means of compressed air (see also sectional view item 3.1.1) 45 30 15 Maintenance of Air Valve 1 : - Screw out seat and blow through - Clean valve seal (see also sectional view item 3.1.1) On start-up of the valve once again (perform above steps in reverse order) venting must be clearly audible (loud hiss) during screwing in of the spindle support. Otherwise the procedure has to be repeated. 18
8.3.2 Maintenance of Air Valve Set Model 985 All maintenance and service work can be done from the road surface, thus avoiding the dangers involved with entering manholes. The Air Valve can be flushed without being dismantled via the two flushing ports (5a / 5b). To this end hoses must be connected to the two flushing ports (5a / 5b) in such a way that the inside pressure is released safely after opening the ball valves (4 / 6). Flushing is performed by passing water from 5a to 5b, possibly adding some cleaning agent. If there are any foreign bodies in the valve that cannot be flushed out via the bottom flushing orifice, the valve should be dismantled, opened, and the foreign body be removed. To this end proceed as follows: 1. Take off the cover (1) from the chamber cylinder (2). Close the shut-off valve by means of the offset operating tube (3) by a half turn (clockwise). The operating tube must be offset by 180 before! Warning: Even after closing the shut-off valve the air valve is pressurized, therefore open the ball valve (4) on the lateral flushing pipe carefully and only after mounting a hose at the flushing port provided for this purpose (5b). Discharge any emerging waste water safely. Dismantle the 3/2-way ball valve (6). To this end loosen the screwed union. 11 2 1 5a 6 5b 4 2. Pull the operating tube (3) upward and out of the air valve set. Turn the valve (7) counterclockwise until the bayonet coupling (8) is loosened. Pull the valve upward and out of the chamber cylinder (2) at the two eye bolts (9) by means of a suitable lifting tool. Any residual water is discharged via the drainage device. If this is not desired, install an end fitting (13) and pump out the chamber. 9 10 3 3. Open the body screws (10). Clean the valve inside (use a cleaning solution, if required, in case of persistent dirt, let the agent work itself in for a while, before cleaning by means of a brush). Screw the valve bonnet (11) back on again, making sure that the toroidal sealing ring is fitting properly. Prior to installation of the Air Valve clean all sealing surfaces. 7 8 12 4. Put the valve (7) onto the bayonet coupling from above and lock it clockwise. Put the 3/2-way ball valve (6) back in place and tighten the screwed unions manually until the connections are tight. Put on the operating tube (3). Close the ball valve of the lower flushing orifice (4). Slowly open the shut-off valve (12) below the air valve (counterclockwise). After opening offset the operating tube again by 180 (safety function against automatic unlocking of the Air Valve). Visual inspection of all connections and flushing orifices. 13 19
9. Specification 9.1 Air Valves Air Valves Model 987 Specification: Air Valve For Water Service ( #987; 1 ) The valve shall be a combination air/vacuum single orifice automatic air release valve with 1 connection to the pipeline. The valve shall be of corrosion free materials, single orifice for allow air to escape and enter in the event of a vacuum condition. The valve shall be of one piece body design. Body and float shall be Delrin (Polyoximethylene, POM). The seat and valve plug made of CuAl10. The valve sealing is rubber made of EPDM. The valve shall have a protection cap of PE. Air and vacuum valves shall be manufactured by Hawle Specification: Air Valve For Water Service ( #987; 2 ) The valve shall be a combination air/vacuum double orifice automatic air release valve with 2 connection to the pipeline. The valve shall be of one piece body design. The internal parts shall have a small orifice within tripod for small air discharge and a big orifice within bonnet of base housing for main air discharge and allow air to enter in the event of a vacuum condition. The material of the body and the flow shall be Delrin ( Polyoximethylene, POM ). The valve sealing is rubber made of EPDM. The valve shall have a protection cap of PE. Air and vacuum valves shall be manufactured by Hawle Air Valve for Sewage ans Water Service 986 Specification: Combination Air Valves shall conform to the following: Automatic Air and Vacuum Valves shall be infinitely variable automatic air and vacuum valves designed to allow escape of air for a operating range starting from pressure range: 0,0 through 250 psi ( 0 17,2 bar ), close watertight when liquid enters the valve even when the fluid is rising without pressure ( no minimum operating pressure required), allow air to enter in the event of a vacuum, and soft working behavior as water hammer inhibition realized by roll-on diaphragm and spring mechanism. When the sealing device of the valve is closed an air cushion is trapped between the fluid and sealing area, a mud deflector made of PE allows no contact between fluid and sealing area. The valve body and spindle spring shall be stainless steel grade 316Ti, designed to facilitate disassembly for cleaning and maintenance. The float shall be Delrin ( Polyoximethylene, POM ); the valve seat and all working parts shall be of corrosion resistant materials. Valves shall be equipped with the necessary attachments, including ball valve, to permit back flushing after installation without dismantling the valve. Valves shall be recommended by the manufacturer for wastewater service. Air and vacuum valves shall be manufactured by Hawle. 20
9.2 Air Valve sets Automatic Air Valve Set ( #992 ) Valve with Shaft for Underground Installation Automatic air valve with standpipe of stainless steel (replacing a shaft), BAIO spigot end or flanged connection drilled, of Ductile Iron (GJS-400), high-quality corrosion protection by fluidized bed epoxy powder coating inside and outside. The valve shall be a combination air/vacuum double orifice automatic air release valve. The valve shall be of one piece body design. The internal parts shall have a small orifice within tripod for small air discharge and a big orifice within bonnet of base housing for main air discharge and allow air to enter in the event of a vacuum condition. The material of the body and the flow shall be Delrin ( Polyoximethylene, POM ). The valve sealing is rubber made of EPDM. Standpipe of stainless steel suitable for above ground and underground installation, standpipe with drain-off fitting. Air and vacuum valves shall be manufactured by Hawle. Air Valve Set for Operating Range 0 250 psi / 0 17,2 bar ( #985 ) Automatic Air and Vacuum Valves shall be infinitely variable automatic air and vacuum valves designed to allow escape of air for a operating range starting from pressure range: 0,0 through 250 psi ( 0 17,2 bar ), close watertight when liquid enters the valve even when the fluid is rising without pressure ( no minimum operating pressure required), allow air to enter in the event of a vacuum, and soft working behaviour as water hammer inhibition realized by roll-on diaphragm and spring mechanism. When the sealing device of the valve is closed an air cushion is trapped between the fluid and sealing area, a mud deflector made of PE allows no contact between fluid and sealing area. The valve body and spindle spring shall be stainless steel grade 316Ti, designed to facilitate disassembly for cleaning and maintenance. The float shall be Delrin ( Polyoximethylene, POM ); the valve seat and all working parts shall be of corrosion resistant materials. Valves shall be equipped with the necessary attachments, including ball valve, to permit back flushing after installation without dismantling the valve. Valves shall be recommended by the manufacturer for wastewater service. The air valve set is provided with a PE shaft replacing a manhole, a shut-off device with a steel plate of hard-rolled stainless steel and straight-through bore when open, two maintenance outlets with hose connection and ball valve, lateral outlet for waste air with PE elbow as swivelling device equipped with additional protection grid, drain-off fitting at the shaft bottom. After closing the shut-off device by integrated operating tool and removal of the upper ball valve the air valve can be taken out of the shaft for maintenance purposes. Valves shall be recommended by the manufacturer for wastewater service. Air and vacuum valves shall be manufactured by Hawle 21
Air Valve Set Model 985 with spigot end Air Valve Set Model 985 with flange Air Valve Set Model 985 with PE tail Medium: raw and potable water, domestic and industrial waste water Operating range: 0 16 bar Component 80 Material 1 Spigot end 80 GGG 40, fluidized bed epoxy powder coated 2 Shut-off facility GGG 40, fluidized bed epoxy powder coated 3 Air Valve steel, St. 37 fluidized bed epoxy powder coated 4 Chamber cylinder PE 5 Cover PE 6 Three-way ball valve PVC 7 Hose coupling PA 6 GF 25 8 Ball valve stainless steel 9 Operating rod square steel St. 37 fluidized bed epoxy powder coated 10 Bottom plate sheet steel St. 37 fluidized bed epoxy powder coated 11 Drain-off fitting GGG 40, fluidized bed epoxy powder coated Accessories 12 End fitting (please observe surcharge!) POM 13 Manhole cover GGG 40, bituminized Manhole ring GG 24, bituminized Drawing representing Air Valve Set with BAIO spigot end 3 22 23
Automatic Air Valve Set Model 992 with spigot end Automatic Air Valve Set Model 992 with flange Automatic Air Valve Set Model 992 with PE tail Medium: potable water Operating pressure: 14.5-250 PSI (0,1 6 bar) and 1.5-87 PSI (0,1-6 bar) Component Material 1.1 Inlet flange GGG 40 1.2.1 Fitting GGG 40 1.2.2 O-ring NBR 1.2.3 Grip ring POM 1.3 O-ring NBR 1.4 Sealing flange Rg 7 1.5 Foot valve POM 1.6 Spring case MS 58 1.7 Pressure spring stainless steel 1.8 Hexagon screw M 10 x 35 DIN 933 stainless steel 2.1 Bonnet POM 2.2 O-ring NBR 2.3 Seat CuZn35Pb3As / EPDM 2.3.1 Hexagon screw stainless steel 2.4 Locking plate stainless steel 2.5 Locknut MS 58 2.6.1 Bottom part of body POM 2.6.2 Air valve support POM 2.7.1 Float bottom part POM 2.7.2 Ballast EPDM 2.7.3 Float top part POM / EPDM 2.7.4 Sealing screw stainless steel 2.7.5 Fan type lock washer stainless steel 2.8.1 Sealing cover POM 2.8.2 Seat for sealing cover EPDM 2.8.3 O-ring NBR 2.9 O-ring NBR 2.10 Hexagon nut stainless steel 2.11 Washer stainless steel 2.12 Hexagon socket bolt stainless steel 2.13 O-ring NBR 2.14 Insect protective grid stainless steel 3 Operating tube stainless steel 4 Centring cap GGG 400 4.1 Hexagon screw M 8 x 10 DIN 931 stainless steel 5 Stand pipe stainless steel 6 Lock ring GGG 40 7 Hexagon bolt M 16 x 50 DIN 931 stainless steel 8 Hexagon nut M 16 DIN 934 stainless steel 9 Washer stainless steel 10 Sealing EPDM 11 Cover EPDM 12 Spindle support GGG 40 13 Operating screw Ms 58 14 Hood PE 15 Hexagon screw M 8 x 60 DIN 931 stainless steel 16 Washer stainless steel 17 Drain pipe PE The following abbreviations are used: AV = air valve AVS = air valve set ARV = air release valve 17
Edition September 2009- Subject to change 1700 Enterprise Way, Suite 116 Marietta, GA 30067 Phone +1 770-818-0670 Fax: +1 770-818-0671