Are you from Valve Engineering Field? Are you interested to gain some education/knowledge of valves? Are you interested to know something about inlet and outlet valves of compressor? If the answer is YES then you are at right place. Valves are very important part in any reciprocating air compressor. The performance of air compressor is mostly depending upon the condition of suction and discharge valves. That’s why due care must be required. Every valve requires a periodic inspection and maintenance. Here you will find important information about suction and discharge valves used in Chicago Pneumatic and Kirloskar Pneumatic Air Compressor. (These are plate type valves)To avoid damage to the valves and inner dowel pins, it is suggested to use a simple fixture for dismantle and assemble valves. These fixtures are supplied by compressor manufacturer on chargeable basis or you can manufacture at your engineering unit. The drawing is available in instruction manual. Use proper size spanner for opening and tightening. Never tightened the valve directly in a vice and do not hammer on spanner when loosening or tightening the nut.
Examine all the parts thoroughly after dismantled the valve. Remove carbon formation with help of Trichloroethylene or diesel and light scraping paper or brush. Don’t scratch the valve plate or seat while cleaning. Completely dry out the valves before installing it on compressor. Never use cotton waste to clean the internal parts of valve, use only cloth for drying out. A dry air can be used for this purpose.
When valve plate, damper plate, spring plate shows sign of wear, it is imperative to replace these parts, even if no breakage has occurred. A maximum wear of about 10 % of the total thickness of valve plate is allowed. For highest efficiency of the valve it is important that the seat face is flat and free from any traces of wear, thus preventing valve leakage. If any damage on the seat observed, it is recommended to replace the same. Dew to presence of dowel pins, re-machining or lapping can not be carried out. It is also suggested to use a new valve plate with new valve seat.
A) Do the valve assembly in required sequence. Use fixture for proper tightening of valve nut. Check valve plate for free movement. The best sequence is first valve seat then washer then valve plate then damper plate then spring plate the washer then valve keeper and tight this assembly with nut. (Refer diagram from instruction manual)
B) The hollow side of the thin part in the centre of the valve plate must be placed upward facing, valve keeper.
C) Suction valves are equipped with unloader, the clearance between the valve plate and unloader lifter as well as the clearance between unloading piston and lifter must be checked.
D) Test valves for leakage and insure it made dry after testing. Use air pressure instrument for testing purpose. Never use petrol or diesel or kerosene for inspection as media of operation is air.
E) Valve cover nuts have to be tightened with specific torque by torque wrench.
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