Maintenance, installation and operation instructions

Pressure reducing valve

Abresan Tolou Bahar Roud (ATBR)

1. Important points before installation

• Avoid impact to components when moving.
• Only use special jigs or stands to lift the valve (use of flange holes or steering components is prohibited).
• If the valve has been in storage for more than 2 years, it must be tested and inspected before installation.
• Store valve away from direct sunlight and moisture.
• It is forbidden to bury valve in the ground.
• The surface of the flanges and sealing areas must be thoroughly cleaned before installation.
• Pay attention to the direction of flow on the body (reverse installation = malfunction).
• The use of a canopy is mandatory outdoors.
• Due to the forces exerted by the pressure difference, it is essential to install appropriate supports before and after the valve.
• Allow sufficient space for repairs around the valve.
• The distance between the two pipeline flanges must be at least 20 mm greater than the length of the valve to prevent damage to the gasket.
• The pipes on both sides of the valve must be perfectly aligned and in the same direction.
• Tighten the flange bolts crosswise and evenly.
• Before operation, the pipeline should be flushed to ensure that there are no foreign objects in it.

2. Initial setup steps (ventilation and initial setup)

A) Venting and filling the valve:

1. Open the inlet gas valve.
2. Open the gas valves before and after the pilot.
3. Open the plastic pilot cap, release the lock nut, and loosen its screw.
4. First open the downstream valve and then the upstream valve by half a turn.
5. Open the bleed screw to let the air out, then close it.
6. The upstream valve should be fully open.

b) Initial downstream pressure setting:

1. Open the valve under the downstream pressure gauge.
2. Open the gas valve slowly after the pilot.
3. To increase pressure: Turn the pilot screw clockwise.
4. To reduce pressure: Turn the pilot screw counterclockwise.
5. After adjustment, tighten the lock nut and close the cover.

3. Final adjustment and line filling

• The downstream shut-off valve should be fully open.
• Check the outlet pressure and readjust if necessary.
• Close the valves below the pressure gauge.
• Important: In parallel installation of two valves, the downstream set pressure must be different to allow separate operation for low and high flow rates.

4. Changing the pressure setting during operation

• Open the valves below the pressure gauge.
• Open the pilot cover and loosen its screw.
• To increase pressure: rotate clockwise / To decrease pressure: rotate counterclockwise.
• After adjustment, tighten the nut, close the cap, and close the valves under the pressure gauge.
• Note: During operation, the gas valves before and after the pilot must always be open.

5. Close the valve completely and restart (very important)

The correct way to close the valve:

1. First, close the gas valve before the pilot.
2. Then close the gas valve after the pilot.
3. Warning: Avoid abruptly closing the gas valve before the pilot to prevent damage to the pipe.

Restart method:

• It is enough to open the gas valve after the pilot.

6. Maintenance and inspections

Periodic service (every 6 to 12 months):

• Check and clean filters and pipelines.
• Valve air vent.
• Creating a strong current to wash the inside of the valve.
• Note: If the water quality is poor, the service interval should be reduced to 4 to 6 months.

Annual inspection:

• Fully open the valve and clean all parts.
• Replacing the diaphragm rubber and valve sealing rubber.
• Check the pilot seal and diaphragm (replace if necessary).

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