Send a part number, a photo, or a whole BOM — we supply it and stand behind it. Worldwide shipping to 80+ countries.

Watts 3/4 LF 100XL-4 ASME Section IV Temperature & Pressure Relief Valve - ASME Section IV Temperature & Pressure Relief Valves
WattsASME Section IV Temperature & Pressure Relief Valves

Watts 3/4 LF 100XL-4 ASME Section IV Temperature & Pressure Relief Valve

The WATTS Temperature and Pressure Relief Valve is an ASME Section IV rated valve with a 3/4 in MNPT x 3/4 in FNPT connection size. Its body is constructed of brass, as specified by manufacturer part number 3/4 LF…

SKU 3G-OTH-437108

Also listed as: 34LF100XL4 · 3 4 LF 100XL 4 · 3-4-LF-100XL-4

Brand
Watts
Item
3/4 LF 100XL-4 ASME Section IV Temperature & Pressure Relief Valve
Category
ASME Section IV Temperature & Pressure Relief Valves
Available to Order
Trade pricing by quote — replies within 24h
Qty
WhatsApp an engineerMessage via Telegram
No account needed — your quote request goes straight to our engineers. A free account lets you track quotes and re-order faster.
Worldwide Shipping
Air & sea freight
Datasheet on Request
Technical specs
1-Day Quote
Replies within 24h

Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
Delivery
Same-day or next-business-day delivery within Singapore for in-stock items; 7–14 days for factory-order parts from Europe.
Payment
Invoicing in SGD. PayNow, bank transfer, and corporate PO accepted.
Ships to
Singapore

Technical Specifications

Watts
Manufacturer Part Number
3/4 LF 100XL-4
Type
Brass
Body Material
Brass
Connection Size
3/4 in x 3/4 in

Technical Documents

No technical documents available for this product.
Request documentation
Not sure this is the right part? Get a recommendation.

Need installation or engineering help?

Installation, commissioning, maintenance plans, system design, and bundled product + service quotes — one team handles the full scope.
Talk to an engineer

Ask a question

Watts Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The WATTS Temperature and Pressure Relief Valve is an ASME Section IV rated valve with a 3/4 in MNPT x 3/4 in FNPT connection size. Its body is constructed of brass, as specified by manufacturer part number 3/4 LF 100XL-4.

Frequently Asked Questions

What is a Watts temperature and pressure relief valve used for?

A Watts temperature and pressure relief valve protects water heaters and storage tanks from excessive temperature or pressure. It automatically opens to relieve steam or water when conditions exceed safe limits, preventing catastrophic failure. This ASME Section IV rated brass valve is common in commercial and residential hot water systems.

What are the specifications of the Watts 3/4 LF 100XL-4 valve?

The Watts 3/4 LF 100XL-4 is an ASME Section IV temperature and pressure relief valve with a brass body. It has a 3/4 in MNPT x 3/4 in FNPT connection size. The manufacturer part number is 3/4 LF 100XL-4. It is designed for use on water heaters and storage tanks requiring overpressure and overtemperature protection.

Where to buy a Watts temperature and pressure relief valve worldwide?

3G Electric supplies the Watts 3/4 LF 100XL-4 temperature and pressure relief valve to customers worldwide. We handle full logistics, customs clearance, and delivery to your site. As a global industrial solutions provider, we source genuine Watts valves and support procurement across 14 industrial departments. Contact us for availability and lead time.

How to install a Watts temperature and pressure relief valve?

Install the Watts valve directly into the water heater or tank tapping using thread sealant on the male NPT end. Ensure the discharge pipe is directed downward and terminates in a safe, visible location per local codes. Never install a shutoff valve between the relief valve and the tank. Test operation after installation by lifting the lever briefly.

Used in

Common applications for Watts
Industrial burner gas safety systems — Watts HF2000 filters with GF-series seal kits maintain clean, regulated gas supply to burner pilot and main flame controls
Commercial heating and boiler installations — Modular filter assemblies support preventive maintenance and component replacement without full system shutdown
Process gas delivery pipelines — DN25 through DN125 filter bodies accommodate varying flow rates and inlet pressures across manufacturing and chemical processes
Gas pressure regulation benches — Multi-stage Watts filter platforms integrate with pressure reducers and safety shutoff valves in test and calibration environments
Equipment retrofit and upgrade projects — Available connection sizes and seal kits enable adaptation of newer Watts components into legacy gas control systems
Planned maintenance and spare-parts inventory — Filter seal kits allow facilities to stock consumables in advance, reducing downtime during scheduled gas system servicing

Watts Products

3G Electric supplies Watts asme section iv temperature & pressure relief valves. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

You might also need

Burners & Combustion Pumps & Compressors Spare Parts All Products

Compatible alternatives & equivalents

Cross-referenced by specification & description
This ASME Section IV temperature and pressure relief valve features a brass body with male NPT x female NPT connections. It automatically relieves excess temperature or pressure in hot water heating systems and storage tanks to prevent equipment damage
Watts
This ASME Section IV temperature and pressure relief valve features a brass body with male NPT x female NPT connections. It automatically relieves excess temperature or pressure in hot water heating systems and storage tanks to prevent equipment damage
Brass-bodied temperature and pressure relief valve with 3/4 in male NPT inlet and 3/4 in female NPT outlet. ASME Section IV rated for use on water heaters and storage tanks to automatically relieve excess temperature or pressure
Watts
Brass-bodied temperature and pressure relief valve with 3/4 in male NPT inlet and 3/4 in female NPT outlet. ASME Section IV rated for use on water heaters and storage tanks to automatically relieve excess temperature or pressure
Brass temperature and pressure relief valve with 3/4 in MNPT inlet and 3/4 in FNPT outlet. ASME Section IV rated for use on hot water storage tanks and heating boilers to relieve excess temperature or pressure
Watts
Brass temperature and pressure relief valve with 3/4 in MNPT inlet and 3/4 in FNPT outlet. ASME Section IV rated for use on hot water storage tanks and heating boilers to relieve excess temperature or pressure
This ASME Section IV temperature and pressure relief valve is designed for use on hot water storage tanks and boilers. It automatically opens to discharge water when internal temperature or pressure exceeds safe limits. The valve features a brass body with 3/4 in male NPT inlet and 3/4 in female NPT outlet connections
Watts
This ASME Section IV temperature and pressure relief valve is designed for use on hot water storage tanks and boilers. It automatically opens to discharge water when internal temperature or pressure exceeds safe limits. The valve features a brass body with 3/4 in male NPT inlet and 3/4 in female NPT outlet connections
Brass-bodied temperature and pressure relief valve with male NPT x female NPT connections. Complies with ASME Section IV standards. Used to automatically relieve excess temperature or pressure in hot-water systems, protecting equipment from unsafe conditions
Watts
Brass-bodied temperature and pressure relief valve with male NPT x female NPT connections. Complies with ASME Section IV standards. Used to automatically relieve excess temperature or pressure in hot-water systems, protecting equipment from unsafe conditions

More from Watts

View all Watts parts
This brass-bodied temperature and pressure relief valve has 3/4 in male NPT inlet and 3/4 in female NPT outlet connections. It is rated to ASME Section IV standards for overpressure and overtemperature protection in water heating systems, such as hot water tanks and boilers
Watts
This brass-bodied temperature and pressure relief valve has 3/4 in male NPT inlet and 3/4 in female NPT outlet connections. It is rated to ASME Section IV standards for overpressure and overtemperature protection in water heating systems, such as hot water tanks and boilers
This ASME Section IV rated temperature and pressure relief valve features a brass body with 3/4 in male NPT inlet and 3/4 in female NPT outlet connections. It is designed for overpressure and overtemperature protection in water heating systems, such as hot water tanks and boilers
Watts
This ASME Section IV rated temperature and pressure relief valve features a brass body with 3/4 in male NPT inlet and 3/4 in female NPT outlet connections. It is designed for overpressure and overtemperature protection in water heating systems, such as hot water tanks and boilers
ASME Section IV temperature and pressure relief valve with 3/4 in MNPT x 3/4 in FNPT connections. Body constructed of copper silicon alloy. Used to protect hot water heaters and storage tanks from overpressure and overtemperature conditions
Watts
ASME Section IV temperature and pressure relief valve with 3/4 in MNPT x 3/4 in FNPT connections. Body constructed of copper silicon alloy. Used to protect hot water heaters and storage tanks from overpressure and overtemperature conditions
ASME Section IV temperature and pressure relief valve with 3/4 in MNPT x 3/4 in FNPT connections. Body constructed of copper silicon alloy. Automatically opens to discharge water when temperature or pressure exceeds safe limits, protecting water heaters and storage tanks
Watts
ASME Section IV temperature and pressure relief valve with 3/4 in MNPT x 3/4 in FNPT connections. Body constructed of copper silicon alloy. Automatically opens to discharge water when temperature or pressure exceeds safe limits, protecting water heaters and storage tanks
Copper silicon alloy body temperature and pressure relief valve with 3/4 in MNPT x 3/4 in FNPT connections. ASME Section IV rated for use on hot water storage tanks and boilers to automatically relieve excess temperature or pressure
Watts
Copper silicon alloy body temperature and pressure relief valve with 3/4 in MNPT x 3/4 in FNPT connections. ASME Section IV rated for use on hot water storage tanks and boilers to automatically relieve excess temperature or pressure
This bronze-bodied temperature and pressure relief valve is rated to ASME Section IV standards. It features male NPT by female NPT connections and is used to protect hot water heating systems and storage tanks from excessive temperature or pressure
Watts
This bronze-bodied temperature and pressure relief valve is rated to ASME Section IV standards. It features male NPT by female NPT connections and is used to protect hot water heating systems and storage tanks from excessive temperature or pressure
This ASME Section IV temperature and pressure relief valve is constructed with a copper silicon alloy body. It features a 3/4 in male NPT inlet and a 3/4 in female NPT outlet. Used as a safety device on hot water heating boilers and storage tanks to automatically relieve excess temperature or pressure
Watts
This ASME Section IV temperature and pressure relief valve is constructed with a copper silicon alloy body. It features a 3/4 in male NPT inlet and a 3/4 in female NPT outlet. Used as a safety device on hot water heating boilers and storage tanks to automatically relieve excess temperature or pressure
This ASME Section IV temperature and pressure relief valve is constructed with a copper silicon alloy body and features 3/4 in male NPT inlet and 3/4 in female NPT outlet connections. It is designed to automatically relieve excess temperature or pressure in water heaters and storage tanks, helping prevent system failures in hydronic applications
Watts
This ASME Section IV temperature and pressure relief valve is constructed with a copper silicon alloy body and features 3/4 in male NPT inlet and 3/4 in female NPT outlet connections. It is designed to automatically relieve excess temperature or pressure in water heaters and storage tanks, helping prevent system failures in hydronic applications