Connections:
Threaded (NPT) 1/2", 1", 2"
Flanged ANSI 150, 300, 600

Temperature Range: -20 to +300°F [-29 to +149°C]
Maximum Inlet Pressure: 200 psig [14 barg]
Blanket Pressure Range: 0.5" wc to 6 psig [12.7 mm wc to 0.4 barg]

RA Operation
For small flow requirements, the pilot can be used by itself as a direct spring tank blanketing valve. When used this way, it is designated a Type RA. The only difference in construction is the location of the sense and inlet ports. The sensed pressure acting against the spring force will determine how much, if any, the pilot is to open.

Y1 Operation
Upstream pressure enters the main body and acts upward against the main valve diaphragm. Due to a small unbalanced dome area, the effective area above the diaphragm is slightly larger than below. Shut-off will occur when the dome pressure is equal to the inlet pressure. The sleeve/diaphragm retainer assembly is lightly spring loaded to provide initial closing force when there is no pressure differential across the diaphragm.

The Type Y1 Pilot controls dome pressure in response to tank pressure. A reduction in dome pressure allows the sleeve to move upward off the main seat, permitting flow through the valve. The amount of lift depends on the pressure reduction in the dome. The greater this reduction, the greater the flow. When the downstream pressure is satisfied, the sensed pressure acting on the pilot sense plate will overcome the spring force to close the pilot, which in turn closes the valve. No system fluid is vented to the atmosphere.

BV-1 Operation
The diaphragm and sleeve are replaced by a piston in the main valve for more rugged construction. As with the Y1 Valve, the pilot controls dome pressure. A reduction in dome pressure allows the piston to move horizontally off the seat, permitting flow through the valve. Maximum flow is controlled by the cage orifices.