Watts ST500 1/2 Float Valve, Bronze, MNPT

The Watts ST500 1/2 is a 1/2" standard-duty bronze lever-arm float valve with NPT threaded connections, mounted in-line on the supply pipe rather than through a tank wall. It ships without the float ball and rod, which are ordered separately. It features a bronze body and a buna-n seat. Rated to 125 psi and up to 180°F.

This 1/2 inch standard duty mechanical float valve is used in commercial, industrial, and agricultural applications for controlling water flow. It is ideal for use in air conditioning, refrigeration, and irrigation systems. This valve has a bronze body with 1/2 inch male NPT threaded inlet and outlet connections, cotter pin pivot arm assembly, and plunger assembly with seals. The maximum pressure is 125 psi (8.7 bar).

Features

• Machined flange
• Bronze body
• Serrated arms
• Replaceable seals

Common Questions

Does this include the float ball and rod?

No. Watts bronze float valves ship without the float and rod; order an FLT-C (copper) or FLT-P (polyethylene) float and a 3/8"-16 rod separately.

Can I use it on drinking water?

No. This valve is not certified lead-free and is for non-potable service only — cooling tower and refrigeration make-up, irrigation, livestock watering and tank fill. Do not install it on a potable water supply.

How does it mount?

In-line on the supply pipe using its NPT threaded connections. It has no machined flange, so it is not a through-the-tank-wall valve like the heavy-duty 500-2000 series.

What size float and rod does it take?

The rod thread is 3/8"-16 on the whole bronze float valve line. Float diameter depends on the valve size and the shut-off level you need — check the Watts float valve catalog for the matching FLT-C or FLT-P float.

Specifications

• Type: Float
• Size: 1/2"
• Outlet Size: 1/2"
• Connection: MNPT
• Body Material: Bronze
• Seat / Seal Material: Buna-N
• Max Pressure (psi): 125
• Application: Irrigation
• Pack Quantity: 100
• Country of Origin: Taiwan
• Warranty: 1 Year Limited
• MPN: ST500 1/2
• Temperature: up to 180°F
• Lead-Free: No
• Actuation: Direct Lever-Arm
• Float & Rod Included: No
• Float Material: Copper (FLT-C) or Polyethylene (FLT-P)
• Float Rod Thread: 3/8"-16
• Mounting: Pipe (Threaded)