DIAPHRAGMACTUATED VALVES

	DIAPHRAGM ACTUATED VALVES	RAF MODELS	RAF General Information
\| Description \| Applications \| Available Models \| Installation \| \| Typical Application \| Specification Form \|	RAF 20 Pump Control Hydraulic Control Valve

Description RAF 20 valve regulates the pressure level during the start & shut-off of pumps to protect the pumping assembly & the downstream network. The RAF 20 is applicable, with slightly different layout & switching, for either vertical (deep well) or horizontal (booster) pumps. In both configurations, the RAF 20 is connected electrically to the pump’s control panel. For booster pumps control the RAF 20 is installed on the main line downstream of the pump. Generally the valve protect the booster pump & its engine by sustaining the pressure in starting & shutoff, & function as a check valve otherwise. The valve protects the pump in case of power shutdown by sustaining the pressure downstream the pump. In deep well configurations, the RAF 20 is installed on a tee branch off the main line. It function basically as a pressure relief. Letting a low pressure in starting & shut-off, & closes other wise to enable a gradual pressure buildup. In case of emergency shutdown, the RAF 20 opens to relieve pressure from the vertical pump.	Applications Use Pump Control Hydraulic Valve with any pump to protect the pump housing, the pumping accessories & water lines. protection is needed in both horizontal & vertical pumps. Consult Raphael engineers for the most suitable layout, switching & sizing of pump control valves for your application. Available Models RAF 20 Pump Control Hydraulic Valve for general applications. Pressure rating up to 16 bars.
Installation RAF Pump Control Hydraulic Valve is activated by line pressure & controlled electrically. The same valve, with a different switching is applicable to either vertical or horizontal pumps.
RAF 20- Booster Pump Control Mode Manual: Use the three-way cock to open or close the RAF 20, by turning the handle to O or C, respectively. Automatic: The three-way cock should be positioned at A. Normally, the power is turned OFF & the valve is closed, as illustrated. When the pump is turned ON, the solenoid is energized & its plunger flips to the left. Port 1 of the solenoid closes, port 2 & the vent open. The control chamber of the RAF 20 drain, the RAF opens gradually, allowing the pump to achieve higher outflow. As the RAF 20 opens, the indicator rises to its upper position. When the electric power is turned OFF, from any reason, the solenoid de-energizes, its plunger flips back to the right (as shown), & the RAF 20 gradually closes. The pressure is sustained. In normal shutdown the pump is turned off electrically by the limit switch only after the RAF 20 is completely closed. In case of unexpected shutdown the RAF 20 closes at the same time. Check valves are located on each side of the RAF 20 to ensure its closure. RAF 20- Deep Well Pump Control Mode Automatic: The RAF is installed on a tee branch off the main line. The RAF 20 is normally open to allow low pressure & buildup of full pumping. As the pump is turned ON, a timer starts a countdown & eventually De-energizes the solenoid, the valve closes gradually under increasing pressure. When the power is turned OFF, the RAF 20 opens to relieve the pressure gradually.		RAF 20 Pump Control Valve
Typical Application RAF 20 controls the out flow of a booster pump. The pump’s intake is on the main line at the left. Note also a Quick Relief Valve - RAF 80Q on the right.

Specification Form


Standard RAF 20		Special Features
Complete basic RAF valve as specified above		Enamel/epoxy coating
Self-cleaning screen filter		External heavy duty screen filter
Selecting cock (3-ways)		-
Two check valves		-
Complete RAF indicator & limit switch assembly		A selection of limit switches is available
Assembled solenoid valve		A selection is available
Layout of control board & selected components as specified.		Upon request
Two cock valve		-
3/8" Reinforced Plastic tubing		Copper or stainless steel tubes
Electric Power	AC	24V, 220V, 110V
	DC	12V, 24V