Views: 114 Author: Site Editor Publish Time: 2022-10-14 Origin: Site
Ensure that the inlet pressure is at least 0.4 bar (5 psig) higher than the starting pressure and that the differential pressure (difference between inlet pressure and discharge pressure) is not less than 0.7 bar (10 psig).
Check the inlet filter for debris.
Check for significant gas leaks (air leaks), which indicate worn seals/bores on the air valve, pilot spool and spindle.
Disassemble the pump and check that there are no obstructions or objects in the air passages that could impede the movement of internal parts.
Check that the ball check valve is not sticking. If the material to be pumped is not compatible with the pump elastomer, swelling may occur. Replace the ball check valve and seal with a suitable elastomer. Also, as the check valve balls wear, they become smaller and may become stuck in the valve seat. In this case, replace the ball and seat.
Check for damage to the inner piston, which will prevent the valve spool from moving.
Remove the plug from the exhaust port of the pilot spool.
Connect the test lamp to the two wires leading to the pump and ensure that the lamp cycles on and off. Ensure that the voltage and current requirements of the lamp are the same as the voltage and current requirements of the coil.
Ensure that the valve manual override control (small red knob on the front of the valve) is switched to the "0" position.
Check the pilot pressure vent at the top of the operator/coil assembly to ensure it is not blocked.
Check the air valve for wear. If air is continuously and heavily purged from the exhaust air, the air valve seals may be worn and not work properly. In this case, the valve must be replaced.
Note: Costs can be saved by completely dismantling the valve, cleaning all components and re-lubricating the valve before scrapping it.
Check the air inlet screen and air filter for debris.
Check that the air valve is not sticking and flush the valve with solvent.
Check the valves for wear. If the piston face of the valve has become shiny rather than dull, the valve may be worn out of working tolerance and must be replaced.
Check the centre body rings. If they are excessively worn, they will not seal and air will simply flow through the pump and out the exhaust port. Due to their special construction, use only the rings.
Check that the piston in the air valve is not rotating. This indicates that the guide pin has failed.
Check the type of lubricant used. An oil with a higher viscosity than recommended may cause the piston to seize or run abnormally. It is recommended to use an oil with anti-freeze characteristics (ISO 15-5 weight).