4 SAFETY VALVES 



TYPE E-6 SAFETY VALVE 

 PC. No. Ref. No. Name of Part 



15,890 E-6 safety valve 50 Ib. to 90 lb., complete. 



15.554 2 Body, bushed. 

 9,029 3 Cap nut. 

 10.524 4 Valve. 



10.523 5 Valve stem. 



24,113 6 Spring, 50 lb. to 90 lb. 

 16,087 7 Regulating nut. 



TYPE E-7 SAFETY VALVE 

 PC. No. Ref. No. Name of Part 



15,549 E-7 safety valve, 35 lb. to 75 lb., complete. 



15,538 2 Body, bushed. 

 9,029 3 Cap nut. 



10.524 4 Valve. 

 10,523 5 Valve stem. 



1,498 6 Spring 35 lb. to 75 lb. 



16,087 7 Regulating nut. 



12.797 8 Exhaust -regulating ring. 



12.798 9 Lock-ring. 



OPERATION OF SAFETY VALVES 



The construction of all four types of safety valves is prac. 

 tically the same, except that the E-3 and E-7 valves have an 

 exhaust-regulating ring 8 and lock-ring 9. 



The safety valve operates as follows: Air enters the safety 

 valve and exerts an upward pressure on the under side of the 

 valve 4- When the pressure underneath the valve slightly 

 exceeds the tension of the adjusting spring 6, the valve 4 is 

 raised, and as it rises, a larger area is exposed to the air pressure, 

 which then causes it to move upwards quickly until the stem 

 strikes the cap nut 3. During this movement, the upper end 

 of the two vertical ports in the valve bushing are closed by 

 the valve 4 and the horizontal ports in the bushing and the 

 body 2 are opened. This allows air from the valve chamber 

 to pass to the atmosphere, and as the pressure in this chamber 

 decreases, the adjusting spring moves the valve 4 down toward 

 its seat. During this movement, the horizontal ports are 

 closed and the upper end of the vertical ports in the valve 

 bushing are opened. This allows air from the valve chamber 

 to pass into the chamber above valve 4, from which place it 



