AIR VALVES DESCRIPTION and TECHNICAL DATA. Air Valves General: Technical :

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1 AIR VALVES

2 AIR VALVES DESCRIPTION and TECHNICAL DATA Air Valves General: What is an Air Valve? An air valve is a valve mounted in TEE configuration on a pipeline to discharge or admit air into or out of the pipeline. Why should the air in the pipeline to be controlled? The existence of trapped air in a pipeline under pressure can cause negative effects on system operation and efficiency. Air pockets accumulating at slope sign changing high points reduce the effective crosssection of the pipeline in the location of accumulation, which causes a decrease in the flow rate, and the energy needed to pressurize the waterflow is increased.the overall system efficiency is then reduced. Air pockets beyond some critical quantity in the system even may restrict the whole pipeline from flowing, locking the pipeline. Sources of Air in Water Pipelines The existence of air in a pipeline might be because: Air under atmospheric conditions might stay within the pipeline when the pipeline was filled with water. With the absence of air discharge valves, accumulation of air occur at local high points. Water at normal conditions, pressure ( 101,325 kpa) and temperature ( 25 C), contains approximately 2% (by volume) of dissolved air. Due to the terrain slopes, variations in flow velocity caused by changing pipe diameters, partiallyopen valves, etc. the water flow is subjected to changing pressures and temperatures, and the dissolved air may be released from the water mass, forming into gas, accumulating as air pockets in the local peak points. Air may be drawn into the pipeline at startup of deepwell pumps, and through leaking joints at zones above the hydraulic gradients (negative pressure points). Air can also be admitted into the system by air valves operatingon belowatmospheric pressures. The Types and Functions of AirValves: Kinetic Air / Vacuum Valve ( Double Acting or Single orifice valve): Venting / Kinetic airrelease function :Exhaust large quantities of air from the pipeline when it is filled with water, at low pipeline pressure Vacuum Breaking / Kinetic antivacuum function :Admit large quantities of air into the pipe when it is drained, or when the internal pressure drops below atmospheric pressure due to transient conditions. Automatic Air Release Valves: Releasing small pockets of accumulated air while the pipeline operates under pressure ( Automatic airrelease function). Combination Air Valves (Triple Acting or Double orifice valve) : A valve that perform the functions of both the Kinetic and Automatic operation. Additional Feature NonSlam or Antishock operation (Four Action or Triple orifice Valve) : A valve that senses the excessive air discharge and so the water approach velocity and reducing the air discharge velocity by intensionally sucking the nonslam float upwards but continuing to discharge at some lower rate inducing an air cushion in the pipeline. This function causes the waterflow to pass the critical point slowly and prevents the impact or surge inducing wet close of the air valve. Technical : Types : Single, Double Chamber Features : Double, Triple Acting Sizes : DN50DN300 Pressure Range : PN10 upto PN64 Flanges : ISO, ANSI Operating Temp. : 10 C C Coating : EPOXY Powder RAL RAPHAEL Air Valves 2

3 AIR VALVES DESCRIPTION and TECHNICAL DATA Air Valve Capacity and Sizing : Air Valve sizing depends severeal criteria on at what pressure difference the valve will operate and what consequences will arise at this operating criterion. The criteria are summarized as below. Design for Vacuum: Criterion 1: Full opening of a discharge valve to empty the pipeline at the and of a V, with maximum static pressure. Critical Vacuum Condition. Criterion 2: Having the same geometry of Criterion 1 with a pipe burst opening equal to nominal pipe size at the mazximum static pressure condition. The valve at the beginnig of upslope should have enough capacitiy to admit enough air into the pipeline to replace the downgoing column to overcome vacuum and collapse. Design capacity only for vacuum according to these preceding two criteriasuggest the limit for choking on design. On choking condition the limiting value DeltaP of 0,528 bar (~53 kpa), suggests no remarkeable change beyond ~0,35 bar. To stay on the safe side, The value 0,2 bar DeltaP should not be exceeded. On an Emptying/Filling Rate of 2:1 for pipeline design, This value is to be limited down to 0,10,15 bar. However, even if this value suggests proper operation away from the collapse limit of pipe line, the vacuum will admit unwanted foreign objects causing contamination in the pipe line. So this limiting value for design is outofdate as per the design criteria. Design for Discharge: Criterion 3: When filling the pipeline, choosing a DeltaP of 0,10,15 bar for discharge of air. Air flow velocity at this point of operaiton will exceed 124 m/s. However, capacitywise being good suggested from the former criteria, this value is tremendously high to induce impact on wetclosing of the valve upon arrival of water to point. On nonkinetic designs, this value of air velocity will induce a venturieffect to suck the float closing prematurely, blocking the flow out. The air stays trappred and and there is no possibility that the valve opens as the pressure accumulation pushes the float further to close. On kinetic designs, the floats will not be affected fron the venturieffect, and the air flow will continue until wetclosing. However, the tests and experience for the last decades show that wetclosing at this discharge velocity induces Surge, which implies local pipe bursts. Most of the pipe bursts occur from uncontrolled filling rates and/or wrong selection or mislocation of air valves on pipe line design. Result: Design of an air valve on limiting capacity for protection from vacuum is not a proper approach. Vast experience on last decades shows, local discharge of air beyond 0,05 0,07 bar DeltaP will induce unbearable Surge in the pipeline. This DeltaP suggests an effective discharge velocity of 3035 m/s of air a t the uppermost orifice of the air valve. Beyond this limiting value it is suggested that the opertion of the pipelinefilling is refrained. This limiting air discharge condition is also used for the design of the antishock or nonslam orifices. Design on capacity curves given on manufacturers is necessary, but not sufficient. The designer should follow the limiting criteria on field of operation. On most critical operation, the selection of the air valve should depend on pipe line filling rate. The curves are as in page CAPACITY CURVES RAPHAEL Air Valves 3

4 H H AIR VALVES DIMENSIONS and WEIGHTS L DOUBLE CHAMBER AIR VALVE 3 EFFECT, KINETIC AUTOMATIC COMBINATION ( Air Discharge, Air Intake, Air Release ) This type of air valve is the newgeneration design for the wellknown double chamber air valve. The 3 functions of traditional double chamber design is conserved, combining thermoplastic cylindrical shaped main float for air intake and air discharge fuctions with the stainless steel float for air release function. This gives an advantage on longterm corrosion resistance and longer operatinal lifetime compared to the competitors designs in the market. Functions: 1. Discharge of air in high volume in the pipeline to atmosphere during pipe filling. ( Atmospheric Function) 2. Intake of air in high volume into the pipe line during pipeline emptying (Atmospheric Functio ). 3. Discharge of low volumes of air preventing them to accumulate and form airpockets during pipeline operation (Pressurized Function ) 2 4 SIZE, WEIGHT AND DIMENSIONS, CAPACITY: DN (mm) H (mm) L (mm) Weight (Kg.) Capacity (nl/s)* DN *Capacity is the limited flowrate with Antishock orifice for normal operation. L Technical Data: Nominal Size : DN50 DN300 Nominal Pressure : PN Flange Standard : TS ISO / TS EN Temperature : 10 C C Coating : Electrostatic Epoxy Powder RAL5010 Option : As per order; Body and Cover GSC25, AISI304, AISI316 Floats AISI304 DN Materials: BODY AND COVER EN ASTM UNS DIN GREY CAST IRON GG25 EN GJL250 A4840B F DUCTILE CAST IRON EN A536/ F GGG40 DUCTILE CAST GJS40015 A536/ F IRON GGG50 STEEL EN GJS5007 A216WCB J CASTING GSC25 STAINLESS A351CF8 J SEEL 304 STAINLESS STEEL A351CF8M J STAINLESS STEEL DUPLEX 2205 S DUPLEX STAINLESS STEEL SMO 254 S SMO254 NiAl Bronze FLOATS : STANDARD MATERIALS AISI304, AISI316, HDPE, PP B148 C Pressure Rating PN10/16 PN25 PN40 ANSI150 ANSI300 ANSI600 Body GGG40 GGG40 GSC25 GGG40 GSC25 GSC25 D N Floats ( Single Chamber) Floats ( Double Chamber) FLANGE DRILLINGS : HDPE HDPE HDPE+AISI304 HDPE+AISI304 HP AISI304 HDPE HDPE+AISI304 PN10, PN16, PN25, PN40, ANSI150, ANSI300, ANSI600 PP AISI304 AISI304 RAPHAEL Air Valves 4

5 H H AIR VALVES DIMENSIONS and WEIGHTS SINGLE CHAMBER AIR VALVE L 4 EFFECT, KINETIC AUTOMATIC COMBINATION + ANTISHOCK ( Air Discharge, Air Intake, Air Release + NonSlam Closure) This type of air valve is the new generation design of combination air valve to compansate for the pipeline design and application defects at air discharge criterion. It accomplishes 4 functions in a single chamber rather than the triple funtion in double chamber design, by limiting the air discharge during uncontrolled pipeline filling. Functions: 1. Discharge of air in high volume in the pipeline to atmosphere during pipe filling.( Atmospheric Function) 2. Intake of air in high volume into the pipe line during pipeline emptying. ( Atmospheric Function ) 3. Discharge of low volumes of air preventing them to accumulate and form airpockets during pipeline operation. ( Pressurized Function ) 4. Limiting of the air flow velocity during disharge when uncontrolled or high velocity pipe line filling. D N 2 4 This causes an aircushion in the pipeline, lowering the approach veloity of water running, reducing the risk of induced impact (surge) on reduced speed arrival of water ( wetclosure) of the main float. SIZE, WEIGHT AND DIMENSIONS, CAPACITY DN (mm) H (mm) L (mm) Weight (Kg.) Capacity (nl/s)* *Capacity is the limited flowrate with Antishock orifice for normal operation. Technical Data: Nominal Size : DN50 DN300 Nominal Pressure : PN Flange Standard : TS ISO / TS EN Temperature : 10 C C Coating : Electrostatic Epoxy Powder RAL5010 Option : As per order; Body and Cover GSC25, AISI304, AISI316 Floats AISI304 DN Materials: BODY AND COVER EN ASTM UNS DIN GREY CAST IRON GG25 EN GJL250 A4840B F DUCTILE CAST IRON GGG40 EN GJS40015 A536/ F DUCTILE CAST IRON GGG50 EN GJS5007 A536/ F STEEL CASTING GSC25 A216WCB J STAINLESS SEEL 304 A351CF8 J STAINLESS STEEL 316 A351CF8M J STAINLESS STEEL DUPLEX DUPLEX 2205 S STAINLESS STEEL SMO254 NiAl Bronze FLOATS: SMO 254 B148 AISI304, AISI316, HDPE, PP S C STANDARD MATERIALS PRESSURE RATING PN10/16 PN25 PN40 ANSI150 ANSI300 ANSI600 DN Body Floats GGG40 HDPE GGG40 HDPE GSC25 HP GGG40 HDPE GSC25 PP GSC25 FLANGE DRILLINGS : PN10, PN16, PN25, PN40, ANSI150, ANSI300, ANSI600 RAPHAEL Air Valves 5

6 AIR VALVES TYPES AND LOCATION Air Valve Location on Pipelines : Hydraulic Gradient Line Long Descent Horizontal Run Long Ascent Kinetic Air Discharge/Vacuum Valve Automatic Air Release Valve Combination Air Valve Pump Check Valve Drain Valve Reservoir Air Valve Location on Pipelines: The recommendation of AWWA steel pipe manual on locatgion of air valves on a pipeline is: 1. High Points Combination Valve (Triple Acting) 2. Long Horizontal Lines Air Release or Combination Valve (intervals of ~400 m.~750 m.) (Triple Acting) 3. Long Ascents Air Vacuum Valve (intervals of ~400 m.~750 m.) (Double Acting) 4. Long Descents Combination Air Valve (intervals of ~400 m.~750 m.) (Triple Acting) 5. Increasing change on downslope of line Combination Air Valve (Triple Acting) 6. Decreasing change in upslope of line Air Vacuum Valve (Double Acting) RAPHAEL Air Valves 6

7 AIR VALVES PERFORMANCE CHARTS Main Orifice Discharge Performance Chart Air Flow Chart Line Pressure (bar) Üst OrifisteManometrik Outflow SCFM Intake and Discharge Rates of Free Air Flow Intake nm³/h Outflow nm³/h nm³/h = normal m³/h SCFM: Standard Cubicfeet per second 8 kpa 20ºC psi 68ºF Intake SCFM Line Pressure (psi) Air Release Orifice Discharge Performance Chart p (bar) Q (scfm) Ø1.2mm(Ø0.047")smallorificeDN25(1")&DN50(2")Valves Ø1.5mm(Ø0.059")smallorificeDN80(3")&DN100(4')Valves Ø2.4mm(Ø0.094")smallorificeDN150(6")&DN200(8')Valves Ø3.2mm(Ø0.125")smallorificeDN250(10")&DN300(12')Valves 5 10 Q(nl/s) p (psi) RAPHAEL Air Valves 7

8 AIR VALVES SIZING TO PIPELINE PIPE SIZEI [ mm.] 2400,0 2300,0 2200,0 2100,0 2000,0 1900,0 1800,0 1700,0 1600,0 1500,0 1400,0 1300,0 1200,0 1100,0 1000,0 900,0 800,0 700,0 600,0 500,0 400,0 300,0 200,0 100,0 0,0 DN 300 mm. DN 250 mm. DN 200 mm. DN 150 mm. DN 125 mm. DN 100 mm. DN 80 mm. DN 50 mm. AIR VALVE SIZING CHART KINETIC, FULL BORE DESIGN 0,5 0,75 1 1,25 1,5 1,75 2 2,25 2,5 2,75 3 PIPE FILLING RATE (max.) [ m/s ] 2400,0 AIR VALVE SIZING CHART TRIPLE EFFECT KINETIC, FULL BORE DESIGN DOUBLE PARALLEL INSTALLATION PIPE SIZE [ mm.] 2300,0 2200,0 2100,0 2000,0 1900,0 1800,0 1700,0 1600,0 1500,0 1400,0 1300,0 1200,0 1100,0 2 X DN 300 mm. 2 X DN 250 mm. 2 X DN 200 mm. 1000,0 0,5 0,75 1 1,25 1,5 1,75 2 2,25 2,5 2,75 3 PIPE FILLING RATE (max.) [ m/s ] RAPHAEL Air Valves 8

9 AIR VALVES PARTS LIST ADETAIL Poz No: Product Description Body Cover Bearing Shaft Stop Plate Floater Filter Oring Oring Spring Washer Blind Nut Hexagon Head Spring Washer Hexagon Head Bolt Floater Body Floater Cover Joint Connection Plate Joint Seal Floater Pin Shaft Ring Countersunk Bolt Oring Oring Oring Seal Seal Spring Camshaft Socket Bolt Socket Bolt Bolt Grub Filter Shaft Filter Housing Material Ductile cast iron (GGG40) Steel (St523) Polyethylene (PE300) Rubber (NBR) Rubber (NBR) Galvanized Steel (8.8) Galvanized Steel Ductile cast iron (GGG40) Steel (St37) Stainless Steel Vulcanized Rubber Stainless Steel Rubber (NBR) Rubber (NBR) Rubber (NBR) Polyurethane (PU) Polyurethane (PU) Stainless Steel A RAPHAEL Air Valves 9

10 RAPHAEL valves industries was founded in 1949, almost at the same time that Israel was formed. It is the first Israeli company to develop and manufacture control valves for water supply systems. Today, RAPHAEL is one of the leading industrial enterprises in Israel, the main supplier of pipeline valves in Israel s domestic market and a wellknown international brand in 30 countries. RAPHAEL is part of the international TALIS GROUP. RAPHAEL'S professional management and highly qualified technical staff, along with its extended experience in the industry, are one of the company s major assets. RAPHAEL'S engineering department constantly works on new technical solutions and technology to improve the quality and service life of its products. The company s products are protected by numerous patents and international invention certificates. The company is certified for quality management system of ISO9001, and its products have a variety of regional certificates of compliance, including the Russian GOST. RAPHAEL Air Valves 10

11 TALIS is a leading global provider of premium valves, hydrants and other solutions for water flow control. With a varied range of products, we offer comprehensive solutions for the entire water cycle. From hydrants to butterfly valves. From the knifegate valves to the needle valves. Our experience, innovative technology, global expertise and individual consultation process form the basis for developing sustainable solutions for the efficient handling of the vital resource "water". With over nine strong brands and 25 entities in Germany, France, Spain, Portugal, Italy, Great Britain, the Netherlands, Russia, Po land, Israel, China, the Middle East, Mexico, India, South Africa, Kazakhstan, Peru and Brazil, TALIS is the largest supplier of valve technology and first choice when it comes down to watervalves and services for the whole water cycle. RAPHAEL Air Valves 11

12 RAPHAEL RAPHAEL, founded in 1949, was the first Israeli manufacturer of quality control valves. RAPHAEL s research department constantly strives to introduce new and innovative products and solutions for water control systems including waterworks, sewage, irrigation, Fire Protection and industrial applications. BELGICAST BELGICAST, based in Munguia, Spain, started out as a valve manufacturer for the naval industry in In the 1980s, BELGICAST began to diversify its product range, focusing on products for the water market featuring diameters from 20 mm to mm. BELGICAST gained a worldwide reputation with the development of the softsealing gate valve for use in drinking water. Today, BELGICAST has developed an unmatched know how in desalination solutions. BAYARD BAYARD in Meyzieu, France, is a wellknown specialist for fire hydrants, network protection devices, control valves and pipe fittings. BAYARD supplies a full range of equipment designed to cover all requirements, from the production of fresh water and water supply to domestic metering units and waste water disposal. ERHARD ERHARD is one of the most important manufacturers of water valves in the world with experience dating back over 145 years. Its success story began in 1871 when Johannes Erhard founded a small workshop in Heidenheim, Germany, for producing brass water taps. ERHARD Double eccentric butterfly valves, needle valves and ball valves are recognized by customers around the world as the benchmark for high quality and long life expectancy. experienced engineering teams can provide individual customized solutions for all customers needs. ATPLAS TALIS UK, based in Birmingham and Bridgend (South Wales) in the UK, has a rich history of servicing the water industry, both in the UK and around the world and is a recognised and reliable supplier of the ATPLAS RANGE connection systems for all waterrelated areas. With an extensive range of meter boxes, water fittings and valves for a variety of mains and service pipes, the British company s products stand for certified quality and many years of knowhow. FRISCHHUT In addition to high quality castings for the engineering industry, plant engineering and the building trade, the main business of FRISCHHUT is fittings for the supply Of potable water. Founded more than 60 years ago, the company from Pfarrkirchen, Germany, still orients itself on the tradition and reliability of a family company. Its inhouse foundry also produces cast parts for safetyrelated applications in the fields of mechanical engineering, reinforced concrete and bridgebuilding. UNIJOINT UNIJOINT, based in the Netherlands, offers a comprehensive range of adapters and extensions, pipe couplings, flange adapters and dismantling joints for international pipe standards up to maximum dimensions. Individual customer specific solutions can also be designed and produced. SCHMIEDING SCHMIEDING has established itself as the expert in the TALIS Group in Germany for house connections, repair systems and accessories. SCHMIEDING founded in 1874 is a reliable partner with fast response times to customer requests, supported by its customer oriented warehouse concept. Innovative solutions for sustainable and efficient use of systems like for example no dead space, and the limescale free water meter connection system Kondicht or the SCHMIEDING tapping saddles with EISI connections meet all the requirements for daily use. STRATE For more than 60 years, STRATE in Sarstedt near Hannover, Germany, has stood for efficient and comprehensive product and problemsolving competence in the sewage industry. AWALIFT sewage pumping systems are among the best known products, as evidenced by over 30,000 systems sold. They provide optimum protection from blockage and use highly efficient pumps. RAPHAEL Air Valves 12

13 TALIS is the leadingchoice in the world of shut off and control valves. At TALIS, we have the best solutions for the sustainable use of water and energygeneration, industry and municipalities. With a wide range of products, TALIS offers an extensive line of solutions for the entire water control, hydrants, rotary butterfly valves, knife gate valves or needle valves. Our experience, innovative technology, global knowledge and individual approach lay a foundation for the development of sustainable solutions for the efficient processing of such a vital resource as water. RAPHAEL Valves Industries Ltd Hailan st., North Industrial Zone OrAquiva Israel Tel: Fax: Note: specifications can be changed without notice at any time. Copyright: reproduction without written permission of RAPHAEL is prohibited. RAPHAEL is a registered trademark