Robertshaw Model 83939 Logic Relays

The 83939-B Series is a two-position, five ported, 3-way relay with an internal orifice. It is diaphragm actuated and has a connection which may be used to cancel the actuating pressure.
83939-B Specifications

The No. 83939-C1 Pulse Relay is a two-way, diaphragm-actuated, non-venting, normally open valve. Its design is such that after being pressurized and closed, it will not reopen when pressure is lost at Port 1 unless pressure is also lost at Port 2, or a pressure is introduced at Port 3 to blow the poppet off seat. Also, it has a connection which may be used to cancel the actuating pressure at Port 1
83939-C1 Specifications

The 83939-D Series is a high capacity, two-position, four-ported, 3-way, normally closed diaphragm-actuated relay. This relay will supply pressure from Port S to Port C when the actuating diaphragm is pressurized.
83939-D

The No. 83939-E1 Lockout Relay is a two-way, diaphragm-actuated, non-venting, normally open valve. It is used in the safety system to lock out or block certain portions of the control system or a line in a control system upon receipt of a signal at PORT 1. (See Figure 1).
85026 Datasheet

These relays are two-position, three-ported, 3-way which can be manually (83939-H Series) or manually / pneumatically actuated (83839-F & -G Series).

Models 83939 F, G, H

The 83939-P1 Lockout Relay is a two-position, five-ported, relay designed to prevent the loss of control pressure from those receiver-indicators which monitor variables normally unsafe during the starting period (Class B lockout)..
Lockout Relay Datasheet

The 83939-Q Series Lockout Relay is used in conjunction with a receiver-indicator relay in an alarm or shutdown system.
83939-Q Datasheet