AREA VALVE SERVICE UNITS. Unit 8, McKenzie Industrial Park, Tel No.: 44 (0) 161 428 7200 Bird Hall Lane, Fax No.: 44 (0) 161 428 7010 Stockport, Email: info@p3-phoenix.com U.K., SK3 0SB www.p3-phoenix.com
Contents Page Section Page Product Description General 3 Labeling 3 Pipeline Pressure Sensors 3 Door Monitoring 3 Operation General 4 Authorised Access 4 Emergency Access 4 Safety General 4 Installation General 5 Assembly 5 Surface Mounting 6 Flush Mounting Solid Wall 6 Flush Mounting Partition Wall 6 Labeling 7 Testing General 7 First Fix Testing 7 Second Fix Testing 7 Maintenance General 7 Preventative Maintenance 7 Valve Replacement 8 Spading Off 8 NIST O Ring Replacement 8 Spare Parts Lists General Components 9-2 - AVSU, Emergency Access Rev.3
1. Product Description 1.1 General The Area Valve Service Unit (AVSU) is designed to isolate a gas supply during installation, maintenance and in the event of an emergency. The unit comprises a ball valve, mounted in a fire retardant, heat resistant lockable ABS enclosure and is supplied complete with ø22mm or ø28mm copper stub pipes for brazing to the fixed pipeline system. The AVSU is suitable for flush or surface mounting and is available for oxygen, nitrous oxide, 50% oxygen/50% nitrous oxide mixture, medical air, surgical air and medical vacuum. Access to the valve assembly is either by using the key provided to unlock the enclosure or, in the event of an emergency, by using the emergency release mechanism. The AVSU is complete with non-interchangeable screw thread (NIST) connectors either side of the valve for purging, testing, gas sampling and for the connection of an emergency supply. Each NIST connector incorporates a check valve to prevent leakage when the NIST cap is removed. The unit is supplied with two through spades fitted between the valve and the copper pipe stubs. A blank spade is included to replace a through spade should the valve need isolating for maintenance or future works. The spades are colour coded for identification through spades are white and the blank spade is red. 1.2 Labeling All gas identity labeling is fixed internally and is viewed through the door window. This eases the final fix installation as any door can be fitted to any AVSU. The unit also includes an area label plate beneath the window to which a selfadhesive label identifying the area served by the AVSU can be fixed. 1.3 Pipeline Pressure Sensors The unit has a provision for installing internal pipeline pressure sensors to monitor the downstream pipeline pressure, which in turn, can be connected to the area alarm panel. 1.4 Door Monitoring The unit has a provision for installing a reed switch to monitor the status of the door to identify possible misuse of the emergency release mechanism which will alarm when the door has been opened using the emergency release handle. - 3 - AVSU, Emergency Access Rev.3
2. Operation 2.1 General The AVSU is used to isolate the gas supply in a department/area for maintenance or in an emergency. The gas supply is isolated by rotating the valve handle 90º to the closed position as indicated on the valve cover plate. To reconnect the gas supply, the valve handle is turned back through 90º to the open position indicated on the valve cover plate. The AVSU is used to physically isolate the gas supply, during periods of modification works for example, by inserting a blank spade between the valve and the pipeline. Please refer to section 6.4 for the procedures for spading off. The NIST connectors situated upstream and downstream of the valve can be used for purging, testing, gas sampling and for the connection of an emergency supply. To connect to a NIST connector, unscrew the NIST cap and screw on the connecting equipment. It is only possible to connect the correct gas or vacuum NIST fitting. Upon completion of the procedure, the equipment should be removed, the NIST cap replaced, the door closed and locked and the key returned. 2.2 Authorised Access To gain access to the valve assembly, the key for the door should be obtained from the responsible person. A Permit-to-Work may be required depending on the nature of the work to be carried out. It is advisable to close and lock the door of the AVSU if you need to leave the AVSU during the completion of your work. Upon completion of the work, the door should be closed and locked and the key returned to the responsible person immediately. 2.3 Emergency Access If access is required to the valve assembly in an emergency, this can be achieved without having the key to the door by rotating the red emergency release handle through 45º to unlock the door. The correct key must then be obtained to reset the emergency release mechanism and lock the door. It is not possible to lock the door without the correct key after the emergency release handle has been used. The key should then be returned to the responsible person immediately. To reset the mechanism, insert the correct key and turn through 90º anti-clockwise until the key stops, then turn the key a further 45º past the internal stop (some resistance will be felt). The emergency access handle can then be rotated upwards and the key turned clockwise to lock the door. - 4 - AVSU, Emergency Access Rev.3
3. Safety 3.1 General This equipment should be operated and maintained by personnel who are suitably trained and are fully conversant with HTM 2022, HTM 02-01 and BS EN ISO 7396-1. This equipment should be kept clean and be free from oil and grease at all times. Oil and grease will ignite spontaneously in the presence of oxygen. If you suspect that any equipment is contaminated, do not use it. No attempt should be made to use or modify this equipment for use with a gas other than as identified. This equipment should not be operated at pressures exceeding those stated in HTM 2022, HTM 02-01 and BS EN ISO 7396-1. 4. Installation 4.1 General The AVSU s may be installed in a horizontal array or a vertical array. In either case, it is advisable to maintain the following sequence from left to right or top to bottom. O2; N2O; 50% O2/50% N2O; Medical Air; Surgical Air; Vacuum; When flush mounting AVSU s, ensure that an adequate space is left between units to allow the fitting of the flush surrounds. The AVSU should be installed at a height that is easily accessible by hand. Consideration should be given to furniture or crash rails that may be installed at a later stage of the construction. The AVSU should be installed in a location where access for connecting an emergency supply will not be hindered. 4.2 Assembly 1. Remove the door, flush surround and valve cover plate from the AVSU assembly and store in a safe place. 2. Ensure that a cable entry hole is drilled in the enclosure if a pressure sensor is to be fitted. 3. Determine the position of the AVSU and secure to the wall using suitable fixings ensuring that the unit is horizontal and plumb. IMPORTANT: Ensure that the connection point for the pressure sensor is on the downstream side of the pipeline system. 4. Braze the copper pipe stubs to the fixed pipeline system. If the joints to be brazed are close to the enclosure, take care/precautions to prevent damage to the enclosure. 5. Fit blanking plugs into the pressure sensor connection points (if required). 6. Pressure test the pipeline system. 7. Upon satisfactory completion of the first fix pressure test, install the pressure sensor (if required) and ensure that the cabling works for the sensors are completed. 8. Install the valve cover plate, flush surround and door. 9. Apply the self-adhesive label identifying the areas served by the AVSU to the area label plate, close and lock the door. 10. Fit an identity tag to the keys associated with the AVSU and keep in a safe place. - 5 - AVSU, Emergency Access Rev.3
4.3 Surface Mounting 4.4 Flush Mounting Solid Walls 4.5 Flush Mounting Partition Walls - 6 - AVSU, Emergency Access Rev.3
4.6 Labeling 5. Testing 5.1 General All AVSU s should be pressure tested once incorporated into the fixed pipeline system. The testing is split into two phases as detailed below. The second phase of testing can only be carried out when the first phase has been deemed satisfactory and accepted. 5.2 First Fix Testing This pressure test is carried out when the first fix installation has been completed. The required testing pressures are as stated below or as per the contract specification if different. First fix testing pressures in accordance with HTM 2022/HTM 02-01 are; (a) 10 barg. /10 barg. for compressed medical gas systems. (b) 18 barg./18 barg. for compressed surgical gas systems. (c) 7 barg. /5 barg. for vacuum systems. First fix pressure tests in accordance with BS EN ISO 7396-1 are 1.2 times the maximum pressure which could occur under a single fault condition. 5.3 Second Fix Testing This pressure test is carried out upon completion of the second (final) fix installation with the system pressurised to nominal distribution pressure in accordance with HTM 2022, HTM 02-01 and BS EN ISO 7396-1. 6. Maintenance 6.1 General The AVSU is used mainly to assist in isolating the gas supply during maintenance procedures. However, some minimal maintenance may be required on the unit as detailed below. 6.2 Preventative Maintenance Area valve service units should be subjected to regular inspection and testing as detailed below. Monthly; (a) (b) Visually inspect the enclosure for signs of damage. Check the door is securely locked. - 7 - AVSU, Emergency Access Rev.3
Annually; (a) (b) (c) (d) (e) Open the door and clean any debris from the mounting box. Check the valve operates freely. Check the blank spade is in the box for future use. Check the operation of the emergency release mechanism. Check the AVSU is correctly labelled for the area served. 6.3 Valve Replacement To replace the valve; 1. Obtain a Permit to Work and the correct key. 2. Isolate the gas supply to the AVSU. 3. Unlock and open the door and remove the valve cover plate. 4. Unscrew the hexagon head nuts from either side of the valve and extract the valve. 5. Remove the two through spades and remove the o rings taking care not to scratch the grooves. Install new o rings. 6. Remove the o rings from the brass flanges on the stub pipes taking care not to scratch the grooves. Install new o rings. 7. Offer a new valve and a resealed through spade up to a stub pipe and secure with the hexagon head nut (finger tight). 8. Slide the remaining resealed through spade between the new valve and the other stub pipe and screw on the hexagon head nut (finger tight). 9. Tighten up both hexagon head nuts. 10. Reconnect the gas supply and check for leaks. 11. Replace the valve cover plate, close and lock the door. 12. Return the key to the responsible person. 6.4 Spading Off To insert a blank spade into the valve assembly; 1. Obtain a Permit to Work and the correct key. 2. Unlock and open the door and close the valve. 3. Remove the valve cover plate. 4. Unscrew the hexagon head nuts from the downstream side of the valve and extract the through spade. 5. Insert the blank spade, with its o ring correctly located against the valve outlet, and tighten up the hexagon head nut. 6. Replace the valve cover plate, close and lock the door. The downstream section of the pipeline is now isolated from the upstream supply. 7. Return the key to the responsible person. 6.5 NIST O Ring Replacement 1. Obtain a Permit to Work and the correct key. 2. Unlock and open the door and close the valve. 3. Remove the NIST blank cap and place in the box. 4. Unscrew the serviceable plunger from the NIST body. The captive plunger will substantially reduce the gas flow. - 8 - AVSU, Emergency Access Rev.3
5. Remove the o ring from the serviceable plunger taking care not to scratch the groove. Install a new o ring. 6. Replace the serviceable plunger and check for leaks. 7. Fit the NIST blank cap, close and lock the door. 8. Return the key to the responsible person. 7. Spare Parts Lists 7.1 General Components Item No. Description Part Number 1 AVSU Door Assembly, Emergency Access 1-15000-09 2 22mm AVSU Ball Valve 1-15001-09 3 28mm AVSU Ball Valve 1-15002-09 4 Through Plate, 22mm 1-15003-09 5 Through Plate, 28mm 1-15004-09 6 Blank Plate, 22mm 1-15005-09 7 Blank Plate, 28mm 1-15006-09 8 22mm AVSU O-ring Service Kit 1-15007-09 9 28mm AVSU O-ring Service Kit 1-15028-09 10 Blank NIST Cap 1-15008-09 11 Area Label Plate (for emergency access door) 1-15009-09 12 ID Label, O2 1-15010-01 13 ID Label, N2O 1-15011-02 14 ID Label, O2/N2O 1-15012-03 15 ID Label, Medical Air 1-15013-04 16 ID Label, Surgical Air 1-15014-05 17 ID Label, Vacuum 1-15015-06 18 ID Label, Flow Direction Arrow 1-15016-09 19 Open/Close Valve Cover Plate 1-15025-09 20 AVSU Flush Surround 1-15024-09 21 22mm AVSU Valve Handle 1-15023-09 22 28mm AVSU Valve Handle 1-15027-09 23 NIST Serviceable Plunger 1-15026-09 24 Door lock and keys (for emergency access door) 1-15017-09 25 AVSU Window (for emergency access door) 1-15018-09-9 - AVSU, Emergency Access Rev.3
Due to our policy of continuous product improvement, Phoenix Pipeline Products Ltd. reserve the right to alter dimensions and/or specification without notice although every effort will be made to advise of any such modifications. - 10 - AVSU, Emergency Access Rev.3