the relief valve working principle is as follows: the pressure and suction pressure relief valve spring from the lower part on the disc, the exhaust pressure from the upper on the disc. When the suction of exhaust pressure exceeds a certain value, open the Industrial Valves plate. Due to the upper part of the disc pressure area increases after open the Industrial Valves, make its rapid opening, screw air compressor suction and exhaust cavity connected, exhaust cavity pressure drops rapidly, until a certain pressure difference, the disc automatically shut down again. In the closed state, the relief valve shall ensure air tightness. Through adjusting screw to adjust opening pressure, adjust the pre-tightening force of spring. General provisions, R12 compressor exhaust pressure and suction pressure shall not exceed 1470 kPa (the difference between the 15 kg/cm：) , R22 screw air compressor and ammonia compressor exhaust pressure and suction pressure shall not exceed 1666 kPa (the difference between the 17 kg/cm) 。 When more than the value specified above, the safety valve will automatically open. When the exhaust pressure and the difference between the suction pressure is 196 x 294 kPa ( 2×3kg/cm) When the relief valve automatically shut down. The relief valve should be opened and closed under prescribed pressure test and gas tightness test. After adjustment, the lock nut application lead seal lock, should not be opened easily. Once applied, the relief Industrial Valves sealing surface of valve mouth is mechanical wear and chemical etching, and together with impurities.

Collectively, the effect of double flanged gate valve on industrial society has been to eliminate os & y valve fire protection and drastically reduce the time long associated with os&y valve.
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