The 2353-501 and 502 Diverting Relays are snap-acting devices with adjustable set points. They are designed for a variety of switching and interlocking functions in pneumatic control systems where the application requires one or more of the following functions: feeding and exhausting branch lines, diverting a supply line to either one of two branch lines, or diverting one of two supply lines to one branch line. The primary function of these devices is to convert a proportional pneumatic signal, at a predetermined setting, into a positive signal for a final control device. The 2353-503 is a non-adjustable, snap acting, signal comparing diverting relay designed for use in pneumatic control systems where the application requires a pneumatic switching function based on the comparison of two proportional pneumatic input signals. Its primary function is the comparison of two input signals from outside and inside enthalpy transmitters, providing SPDT pneumatic two-position switching based on the transmitted enthalpy values, however, it may be used with any two pneumatic input signals up to a maximum of 30 psig.