½-Inch Scald Protection Valve Assembly with Strainer Tee

Product Description

½-Inch Scald Protection Valve Assembly with Strainer Tee – 03900003

The Encon 03900003 is a ½-inch NPT scald protection retrofit and replacement assembly for compatible Encon combination emergency shower/eyewash and eye/facewash stations. The self-actuating valve opens when the sensed temperature reaches 105°F (40.6°C), allowing overheated water to discharge before it reaches the emergency fixture. As cooler supply water reaches the valve, it closes at approximately 94°F (34.4°C).

An Encon-built strainer tee with a cleanable, reusable 16-mesh 304 stainless steel screen helps intercept debris before it reaches the scald protection valve. The valve operates mechanically and requires no electrical power, wiring, external sensor, or control signal.

Highlights

• Complete scald protection retrofit and replacement assembly
• Designed for compatible Encon combination emergency shower/eyewash and eye/facewash stations
• Helps discharge overheated water caused by solar exposure, heat tracing, process heat, or other uncontrolled heat sources
• ½-inch NPT male threaded station connection
• Opens at 105°F (40.6°C)
• Closes at approximately 94°F (34.4°C)
• Ambient-sensing, standard-flow operation
• Self-actuating design requires no electrical power or control signal
• Serviceable Encon strainer tee with reusable 16-mesh screen
• Hand-removable strainer cap provides convenient screen access
• 300-series stainless steel valve body
• Valve component rated for a maximum operating pressure of 200 psig (13.8 bar)

Automatic scald protection for compatible Encon equipment

Emergency shower and eyewash piping exposed to solar radiation, steam tracing, electric heat tracing, process heat, or other uncontrolled heat sources can retain water at temperatures that may present a scalding hazard during equipment activation.

The 03900003 is intended to help reduce this hazard by automatically establishing an exterior discharge path when excessive temperatures are detected. The assembly allows overheated water to discharge while cooler supply water replaces it within the piping.

The assembly can be used as a retrofit on compatible Encon emergency equipment or as a replacement for an existing 03900003 installation.

How the temperature-controlled valve operates

In its standard-flow configuration, the internal thermal actuator initially responds to the ambient temperature surrounding the valve. When the sensed temperature reaches 105°F (40.6°C), the valve opens and establishes discharge flow.

Once flow begins, the actuator responds to the temperature of the water passing through the valve. Cooler supply water backfills the piping and causes the valve to close at approximately 94°F (34.4°C).

This automatic operating cycle helps remove overheated water from exposed piping without relying on personnel to open and close a manual drain valve.

Serviceable 16-mesh strainer tee

The Encon strainer tee helps intercept particulate before it reaches the scald protection valve. Its serviceable construction includes:

• Chrome-plated brass tee body
• Chrome-plated brass removable strainer cap
• Cleanable and reusable 16-mesh 304 stainless steel screen
• EPDM O-ring
• Schedule 40, 304 stainless steel close nipple

After the station water supply has been shut off and pressure has been relieved, the strainer cap can normally be removed by hand. The screen can then be removed, cleaned, inspected, and returned to service. Inspect the EPDM O-ring whenever the strainer is opened and replace it if it is damaged, worn, or deteriorated.

Installation considerations

Install the 03900003 only on a compatible Encon station and in accordance with Encon IOM 01999964, Revision B. Important installation considerations include:

• Shut off the station water supply and flush the piping before installation, replacement, or plumbing maintenance.
• Attach the assembly’s ½-inch threaded male fitting to the applicable station tee or accessory fitting.
• Install the assembly with the valve’s flow-direction arrow pointing downward toward the intended discharge location.
• Use an appropriate pipe wrench and pipe-thread sealant when attaching the components.
• Route discharged water to an appropriate drain or disposal location.
• Place the assembly where it will be exposed to the same source of overheating as the piping requiring protection.
• After installation, inspect all connections for leakage and activate the emergency station to verify the proper flow pattern and water volume.
• Recommended station dynamic, or flowing, water pressure is 30–80 psi.

The station’s recommended 30–80 psi dynamic pressure range is separate from the valve component’s 200 psig maximum operating-pressure rating.

Additional fittings may be required, depending on the station configuration:

• Eyewash station installation: Encon recommends using self-draining ball valve P/N 00011037, sold separately.
• Combination shower/eyewash station using both freeze and scald protection assemblies: Accessory Tee Assembly P/N 01052082 is required and sold separately.
• Eye/facewash station using one protection assembly: Accessory Tee Assembly P/N 01052082 is required and sold separately.
• Eye/facewash station using both freeze and scald protection assemblies: ½-inch cross fitting P/N 00001704 and ½-inch close threaded nipple P/N 00006801 are required and sold separately.

When the assembly is connected only at the fountain-section midpoint of a combination station, its ability to respond to conditions in other sections of the station may be limited. Installation location should allow the valve to sense the same overheating conditions affecting the piping that requires protection.

Operation and maintenance

Activate the complete plumbed emergency shower or eye/facewash station weekly to flush the supply lines and verify the proper flow pattern and water volume. Maintain test records in accordance with the facility’s inspection and compliance procedures.

Periodically inspect the scald protection assembly for leakage, damage, obstruction, accumulated debris, and unrestricted discharge. Establish the strainer inspection and cleaning frequency according to facility water quality, observed debris accumulation, operating conditions, and the site’s preventive-maintenance program.

To service the strainer:

1. Shut off the station water supply.
2. Relieve pressure from the piping.
3. Remove the strainer cap by hand.
4. Remove and clean the reusable screen.
5. Inspect the screen and EPDM O-ring.
6. Replace any damaged or deteriorated component.
7. Reassemble the strainer.
8. Restore the water supply and inspect the assembly for leakage.
9. Activate the emergency station and verify its proper flow pattern and water volume.

Do not remove the strainer cap while the assembly is pressurized.

Construction and performance details

• SKU: 03900003
• Product type: Scald protection retrofit and replacement assembly with strainer tee
• Station connection: ½-inch NPT male threaded fitting
• Sensing configuration: Ambient sensing
• Flow configuration: Standard flow
• Opening temperature: 105°F (40.6°C)
• Closing temperature: Approximately 94°F (34.4°C)
• Maximum valve operating pressure: 200 psig (13.8 bar)
• Maximum valve operating temperature: Up to 150°F (83.3°C) above the setpoint, not to exceed 300°F (149°C)
• Valve body: 300-series stainless steel
• Internal valve materials: 300-series stainless steel, EPDM, and FEP-encapsulated Viton®
• Strainer tee body: Chrome-plated brass
• Removable strainer cap: Chrome-plated brass
• Strainer screen: 16-mesh 304 stainless steel; cleanable and reusable
• Strainer O-ring: EPDM
• Close nipple: Schedule 40, 304 stainless steel
• External power required: None

Valve component dimensions:

• Diameter: 1.3 inches (33 mm)
• Length: 4.5 inches (114 mm)
• Weight: 0.9 lb (0.4 kg)

The dimensions and weight above apply only to the scald protection valve component. They do not include the Encon strainer tee and do not represent the complete installed assembly envelope.

FAQs

What is included with the 03900003 assembly?

The assembly includes a self-actuating scald protection valve and an Encon strainer tee. The strainer tee incorporates a chrome-plated brass body and removable cap, a reusable 16-mesh 304 stainless steel screen, an EPDM O-ring, and a Schedule 40, 304 stainless steel close nipple.

At what temperature does the scald protection valve open?

The valve opens when the sensed temperature reaches 105°F (40.6°C).

At what temperature does the valve close?

The valve closes at approximately 94°F (34.4°C) as cooler supply water reaches the thermal actuator.

What can cause water in emergency equipment piping to overheat?

Potential heat sources include direct solar exposure, steam tracing, electric heat tracing, nearby process equipment, and other uncontrolled environmental or process heat sources.

Does the assembly require electricity?

No. The scald protection valve is self-actuating and requires no electrical power, wiring, external sensor, or control signal.

Can the strainer screen be cleaned and reused?

Yes. After the water supply has been isolated and pressure has been relieved, the removable strainer cap can be taken off by hand. The 304 stainless steel screen is intended to be cleaned, inspected, and reused.

How often should the strainer screen be cleaned?

No fixed strainer-cleaning interval is specified. Inspection and cleaning frequency should be based on facility water quality, debris accumulation, operating history, and the site’s preventive-maintenance program.

Are the technical drawing dimensions the overall dimensions of the complete assembly?

No. The published 1.3-inch diameter, 4.5-inch length, and 0.9-pound weight apply only to the scald protection valve component. They do not include the Encon strainer tee.

Will additional fittings be required?

Possibly. Requirements depend on the type of Encon station and whether freeze protection, scald protection, or both assemblies are being installed. Review Encon IOM 01999964, Revision B before ordering or installation.

Does this assembly replace a tempered water system?

No. The assembly is intended to discharge overheated water retained in compatible emergency-equipment piping. It does not heat, cool, blend, store, or continuously supply tempered water and should not be treated as a substitute for a properly designed tempered water system.

Does the assembly guarantee that water at the emergency fixture will always remain below the opening temperature?

No. Performance depends on correct product selection, installation location, exposure to the applicable heat source, unrestricted discharge, water-supply conditions, and regular maintenance. The facility remains responsible for evaluating the complete emergency-water system and its operating environment.

Specifications

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