What is Test and Drain Valve and Where It Is Used?

What Is The Test and Drain Valve?

Test and drain valve is one kind of 3 way ball valve which has the function of testing, draining and closing the water flow at different status. It is used in firefighting alarm valve system. Compared with other drain valve, it includes double sight glasses to observe and confirm liquid flow through sight glass when open or close the valves.

It offers one step to resolve multi -requirements on the installation and maintenance of wet pipe fire sprinkler systems.

What Are The Materials And Features For Each Part？

• Body
  The valve’s body is made of brass (C37710), which has excellent cutting performance, wear resistance and high strength.

• Valve’s Nut
  The valve’s nut can be made of brass (C37710) or low carbon steel (SM20C). When the low carbon steel material is used, the surface shall be chrome plated for anti-corrosion treatment.

• Sight Glass
  The material of the sight glass is transparent explosion-proof plastic (PV), which has the good performance of corrosion resistance and pressure resistance.

• Soft Sealing Parts
  The O-ring and gasket used for the sight glass and connecting nuts are made of silicon rubber in superior elasticity, and the other soft sealing materials are made of EPDM.

• Valve’s Sealing Seat
  The valve’s sealing seat is made of PTFE and the valve ’ s ball is made of brass in chrome plating, which has good lubricity, sealing, wear resistance and corrosion resistance.

• Handle and Screw
  The handle is made of steel plate (Q235) in chrome plated.
  The screw is made of stainless steel (S304) in anti loosening standard.

Where Is The Test and Drain Valve Used?

• The test and drain valve is conventionally positioned at the end of the sprinkler system, serving as a means to facilitate flow testing.

• This valve is commonly used in multi-story buildings. In such buildings, sectional valves are typically installed in the stairwell on each floor, accompanied by a test and drain assembly. This assembly not only allows for testing the alarm switch on the sectional valve but also enables system drainage if necessary.

• The testing component of the drain consists of a preinstalled restricted orifice, which mimics the discharge of a sprinkler head. To flow through this restricted orifice, the valve handle must be positioned in a specific manner.