THE OCV MODEL 120

• The OCV Model 120 rate-of-flow control valve is designed to control or limit flow to a constant, predetermined rate regardless of fluctuations in upstream or downstream pressure. It consists of the following components.

1. Model 65 Basic Valve, a hydraulically-operated, diaphragm-actuated, globe or angle valve with an elastomer-on-metal seal and throttling seat retainer.
2. Orifice Plate, installed integral to the main valve’s inlet flange. The orifice plate is the flow-sensing device for the rate-of-flow pilot. Orifice plate bore is sized for application flow range.
3. Model 2450 Rate-of-Flow Control Pilot, a two-way, normally-open pilot valve that senses the differential pressure created across the orifice plate and balances it against an adjustable spring load. This differential is proportional to the flow rate through the valve. An increase in differential tends to make the pilot close.
4. Model 126 Ejector, a simple “tee” fitting with a fixed orifice in its upstream port. It provides the proper pressure to the diaphragm chamber of the main valve depending on the position of the rate-of-flow pilot.
5. Model 141-2 Needle Valve, that controls the opening and closing speed of the main valve.
6. Model 159 Y-Strainer (standard on water service valves), The strainer protects the pilot system from solid contaminants in the line fluid.
7. Two Model 141-4 Ball Valves (standard on water service valves, optional on fuel service valves), useful for isolating the pilot system for maintenance or troubleshooting.