Air Fittings – Safety Check Valves

	Check Valve in Open Position	Check Valve in Closed Position

Application:

• Conforms to OSHA regulation 1026.302 (b) (7) requiring a safety device at the source of the air supply and at branch air lines.
• Applications include temporary plant/factory air, construction sites, shipyards or utilities.

  Features:

• High flow valve to provide optimum performance.
• Controls excess air flow (SCFM) in only one direction.
• Automatically senses change in air flow and shuts off the flow in the event of a surge in excess of valve flow rating thus preventing hose whip.
• Not for use in applications where 100% of the available air is required, i.e. sand blast, pile driving rigs, expansion joint blow down pipes, etc.
• Does not prevent backflow.

  Construction:

• Solid brass body and valve.
• Stianless steel spring and roll pin.
• Maximum Pressure: 250 PSI
• Maximum Temperature: 250°F

  Use:

• Safety check valves operate by using the pressure differential across the valve to operate the valve and spring assembly. The pressure differential is directly related to the flow of air (SCFM) through the valve.
• When the pressure differential is within the operating limits – below the cutoff flow – of the unit, the force on the valve exerted by the spring is greater than that caused by the pressure differential (see “Open Position” graphic). The valve remains open and normal operation continues.
• When the pressure differential is above the cutoff limit, the force on the valve exerted by the pressure differential is greater than the force exerted by the spring, and the valve closes (see “Closed Position” graphic).
• After the repair is made, normal operation is automatically enabled when pressure across the valve equalizes through the bleeder hole.
• The valve spring size can be specified by determining the air flow during normal operation and by estimating the air flow if a failure or rupture occurs.
  

  Part #	NPT and Hose ID Size	Cut-off Flow Rate (SCFM at 90psi)		Part #	NPT and Hose ID Size	Cut-off Flow Rate (SCFM at 90psi)
  SCVL2	1/4″	23-29		SCVL10	1-1/4″	260-290
  SCVM3	3/8″	39-47		SCVM10		300-340
  SCVS3		52-65		SCVS10		440-500
  SCVM4	1/2″	70-78		SCVH10		570-630
  SCVS4		80-96		SCVL12	1-1/2″	300-360
  SCVL6	3/4″	72-88		SCVM12		470-530
  SCVM6		92-108		SCVS12		640-720
  SCVR6		112-128		SCVH12		750-830
  SCVJ6		132-148		SCVL16	2″	510-590
  SCVS6		160-180		SCVM16		725-825
  SCVH6		180-200		SCVS16		900-1050
  SCVL8	1″	165-195		SCVH16		1100-1200
  SCVM8		220-260		SCVL24	3″	1200-1400
  SCVS8		280-320		SCVS24		2400-2700
  SCVH8		310-340		SCVH24		2850-3050