SAFETY VALVES 



361 



SAFETY VALVES 



TYPES OF AIR-BRAKE SAFETY VALVES 



Pour types of air-brake safety valves are made; viz., E-l 

 and E-6, which weigh 3 lb., and E-3 and E-7, which weigh 

 3i lb. While types E-l and E-3 are designed for air-brake 

 service, they can be used for any service where a high-grade, 

 air-pressure, safety valve is required. However, the ranges 

 of pressures given must not be departed from as they cover the 



FIG. 1 



FIG. 2 



limits under which satisfactory operation can be obtained 

 from the different springs. The pressure range for which the 

 valve is adapted is now stamped on the hexagon portion of 

 the body. The E-l safety valve, shown in Fig. 1, is suitable 

 for general service where a high-grade, air-pressure, safety valve 

 is required, except where it is necessary to have a close or adjust- 

 able range between the opening and closing points of the safety 

 valve, in which case the type E-3 should be used. 



