The Flomatic 4501SSX 70 Auto-Drain is made of Stainless Steel and opens at 5 psi.

70 - Auto-Drain - This 1" valve is available in stainless steel and PVC. All internal parts are engineered composite with a stainless steel disc and resilient seat.

Specifications:

Max Pressure:  400 psi

Spring Range:  5 psi

Material:  Stainless Steel

Connection:  1" Male NPT

Weight:  0.3 lbs

Case Qty:  12

The Model 70 Automatic Drain Valve automatically opens to atmosphere when water system pressure drops below 5 or 10 (psi). The spring-loaded drain valve operates hydraulically and is designed to close thru the water flow velocity in the pipe. The drain valve will provide automatic drainage of pipe water lines in a water system when the line pressure drops below 5 or 10 psi. No adjustments are necessary.

Operation:

The Model 70 Automatic Drain Valve is normally held open by the force of the compression spring. The Flomatic Valves Auto-Drain Valve Model 70 when properly installed in a water wells riser pipe will drain the piping system when the system pressure is 5 or 10 psi or lower.

NOTE: The Auto-Drain Valve will close automatically when the water flow velocity reaches about 5 GPM or greater in a 1” size pipe.

Flomatic's Model 70 Auto Drain Valves protect domestic water well systems and irrigation systems from freezing throughout winter. This simple yet effective 1 inch valve streamlines the winterization process.

Designed to Automatically Drain Water in:

• Domestic well water systems
• Irrigation and agricultural sprinkler systems
• Dewatering systems

Valve Operation:

• Automatically drains water lines when the line pressure drops below
  5 or 10 PSI in a closed water system (depending on chosen configuration).
• Versatile installation: vertical or horizontal mounting position
  
• Hydraulically operated
• Corrosive resistant material: available in stainless steel and PVC
• Maintenance free

Installation:

The Model 70 Auto Drain Valve should always be installed in an area that would not result in water damage. We recommend installing the valve in a 1" NPT pipe tee fitting. The pipe tee should be located in a 1" or 1 ¼ " water well drop pipe between the submersible pump and ground level. The pipe tee's location should be a maximum vertical distance of 10 feet for 5 PSI (or 20 feet for 10 PSI valve) from the closest drain faucet in the water system. No check valve can be installed between the auto drain valve and drain faucet as it would prevent water system drain back.