The Model VS-SP is a vane type waterflow switch for use on wet sprinkler systems. These devices may be used as sectional flow indicators on large sprinkler systems and on smaller sprinkler systems such as mobile homes and residential dwellings.

The VS-SP does not have a retard to prevent false alarms due to water surges. Therefore it should NOT be used on systems with variable water pressure supplies except in the case of elevator recall.

Unique Features

  • Solid metal enclosure
  • 1" BSPT threads on VS-SPB model

Codes and Approvals

  • NFPA 13, 13D, 13R, 72

Engineering Specifications

Special Application Vant Type Waterflow Alarm Switches: UL, cUL Listed and CE Marked waterflow alarm switches shall be furnished and installed at each sprinkler system branch line connection to the wet pipe main where indicated on the drawings, and as required by NFPA Standards. Mounting shall be by means of a 1 inch TEE fitting installed in the branch line. Vanes shall be field installed on the switch from a selection supplied with the switch and fit pipe sizes 1 inch through 2 inches. Waterflow switches shall be capable of operation in system pressures up to 250 PSI, maximum surges of up to 18 FPS and alarm activation at 10 GPM. Switch configuration shall consist of one single pole double throw (S.P.D.T.) Form C set of contacts rated at 15A, 125 VAC and 2.5A, 30 VDC. It shall be possible to field install an optional second set of switch contacts. Flowswitch enclosure shall meet NEMA 4 rating and shall be held captive by tamper resistant screws or supervised for removal by a cover tamper switch. Connection to piping shall be by means of 1” NPT or 1” BSPT threaded brass bushing. Waterflow alarm vane switch shall be Model VS-SP for NPT threads or VS-SPB for BSPT threads manufactured by Potter Electric Signal Company.

Additional information for Engineers

  • It does not have a retard so it is perfect for use on elevator recall / shutdown or pump and tank systems
  • It comes with 12 different paddles for use on 1" - 2" iron, copper or CPVC tees

Installation Tips

  • Make sure the correct paddle is used for the size and type of tee it is installing in.
  • Do not install in reducing bushings, weld-o-lets or mechanical tees
  • When properly installed, there should be approximately 1 11/16" from the top of the tee to the base of the VS-SP

Tech Tips

  • When the device is in a no flow condition, the switch contacts will be the opposite of what they are marked. The N.O. terminal will be closed and the N.C. terminal will be open when there is no flow. The contacts will reverse upon waterflow.

Additional Information

Click here to view more info about the VS-SP and VS-SPB.

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