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

ARMSTRONG Flange: 1/2 in, LF 1/2" SWEAT UNION HARDWARE KIT, 1/2 in Sweat, 1 1/4 in NPSM - Unions
ARMSTRONGUnions

ARMSTRONG Flange: 1/2 in, LF 1/2" SWEAT UNION HARDWARE KIT, 1/2 in Sweat, 1 1/4 in NPSM

The ARMSTRONG Flange: 1/2 in is a bronze union with a 1/2 in sweat connection and 1 1/4 in NPSM thread, including an EPDM gasket. It is compatible with the ASTRO 225SSU model and is identified by manufacturer part…

SKU 3G-OTH-81185

Also listed as: LF12SWEATUNIONHARDWAREKIT · LF 1 2 SWEAT UNION HARDWARE KIT · LF-1-2-SWEAT-UNION-HARDWARE-KIT

Brand
ARMSTRONG
Item
Flange: 1/2 in, LF 1/2" SWEAT UNION HARDWARE KIT, 1/2 in Sweat, 1 1/4 in NPSM
Category
Unions
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

ARMSTRONG
Manufacturer Part Number
LF 1/2" SWEAT UNION HARDWARE KIT
Type
LF 1/2" SWEAT UNION HARDWARE KIT, Union
NPSM
1 1/4 in
Sweat
1/2 in
Includes
Union
Body Material
Bronze
Gasket Material
EPDM
Compatible with Manufacturer Model Number
ASTRO 225SSU

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

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

Product Description

The ARMSTRONG Flange: 1/2 in is a bronze union with a 1/2 in sweat connection and 1 1/4 in NPSM thread, including an EPDM gasket. It is compatible with the ASTRO 225SSU model and is identified by manufacturer part number LF 1/2" SWEAT UNION HARDWARE KIT.

Frequently Asked Questions

What is the ARMSTRONG LF 1/2" SWEAT UNION HARDWARE KIT used for?

This bronze union is used in plumbing and HVAC systems to connect and disconnect pipes without cutting. It joins 1/2 in sweat copper tubing to 1 1/4 in NPSM threaded fittings, providing a leak-resistant seal with its EPDM gasket.

What are the specifications of the ARMSTRONG 1/2 in sweat union?

The ARMSTRONG union has a 1/2 in sweat connection and 1 1/4 in NPSM thread. It includes a bronze body and an EPDM gasket. The manufacturer part number is LF 1/2" SWEAT UNION HARDWARE KIT, and it is compatible with the ASTRO 225SSU model.

Where to buy the ARMSTRONG LF 1/2" SWEAT UNION HARDWARE KIT worldwide?

3G Electric supplies the ARMSTRONG LF 1/2" SWEAT UNION HARDWARE KIT worldwide. As a global industrial distributor, we handle full logistics, customs clearance, and delivery to your location. Contact us for availability and lead time.

How to install the ARMSTRONG 1/2 in sweat union?

To install, clean and flux the 1/2 in copper tube, then solder it into the sweat end. Tighten the union nut by hand, then use wrenches on the hex flats to secure the 1 1/4 in NPSM threaded connection. Ensure the EPDM gasket is seated properly to prevent leaks.

Used in

Common applications for ARMSTRONG
Hydronic heating systems — ARMSTRONG general-purpose inline circulator pump 182202-657 for potable water circulation
Pump motor replacement — ARMSTRONG pump motor 817025-007 for S&H 4-Series circulator pumps
Flange installation on E32.2HT pumps — ARMSTRONG flange hardware kit 810120-353K with steel bolts and rubber gaskets
Bearing replacement in H-32 series pumps — ARMSTRONG bearing assembly 816549MF-091 for in-line circulating pumps
Piping system connections — ARMSTRONG standard flanges 806074-621k for H-6 6 model with stainless steel and EPDM
Retrofit of pump flanges — ARMSTRONG flange 561100LF-001 for ASTRO EXPRESS 2 SYSTEM union-type connections

ARMSTRONG Products

3G Electric supplies ARMSTRONG unions. 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
ARMSTRONG Union Set: 1/2 in, 810120-220, Compatible with OEM Part No. 32UN12, 1/2 in Sweat
ARMSTRONG
ARMSTRONG Union Set: 1/2 in, 810120-220, Compatible with OEM Part No. 32UN12, 1/2 in Sweat
ARMSTRONG Flange: 1 1/2 in, FLANGE CI 1.5" NPT FS2+HWKIT AST, 1 1/2 in, Flange
ARMSTRONG
ARMSTRONG Flange: 1 1/2 in, FLANGE CI 1.5" NPT FS2+HWKIT AST, 1 1/2 in, Flange
ARMSTRONG
ARMSTRONG
ARMSTRONG Flange: 1 1/4 in, 816011-721K, 1 1/4 in NPT, Flange, 2 Flanges Included
ARMSTRONG
ARMSTRONG
ARMSTRONG Flange: 3/4 in, 816013-621k, 3/4 in NPT, Flange, 2 Flanges Included

More from ARMSTRONG

View all ARMSTRONG parts
ARMSTRONG Flange: 810120-351K, Compatible with OEM Part No. 32UN20, Flange
ARMSTRONG
ARMSTRONG Flange: 810120-351K, Compatible with OEM Part No. 32UN20, Flange
ARMSTRONG Flange: 2 in, FLANGE LF BRZ 2" NPT F4+HWKIT, 2 in, Flange
ARMSTRONG
ARMSTRONG Flange: 2 in, FLANGE LF BRZ 2" NPT F4+HWKIT, 2 in, Flange
ARMSTRONG Flange: 1 1/2 in, FLANGE LF BRZ 1.5" NPT FS2+HWKIT, 1 1/2 in, Flange
ARMSTRONG
ARMSTRONG Flange: 1 1/2 in, FLANGE LF BRZ 1.5" NPT FS2+HWKIT, 1 1/2 in, Flange
ARMSTRONG Union Set: 3/4 in, 810120-222, Compatible with OEM Part No. 32UN12, 3/4 in Sweat
ARMSTRONG
ARMSTRONG Union Set: 3/4 in, 810120-222, Compatible with OEM Part No. 32UN12, 3/4 in Sweat
ARMSTRONG Union Set: 3/4 in, 810120-224, Compatible with OEM Part No. 32UN12, 3/4 in FNPT
ARMSTRONG
ARMSTRONG Union Set: 3/4 in, 810120-224, Compatible with OEM Part No. 32UN12, 3/4 in FNPT
ARMSTRONG Flange: 3/4 in, LF 3/4" FNPT UNION HARDWARE KIT, 3/4 in FNPT, 1 1/4 in NPSM, Union
ARMSTRONG
ARMSTRONG Flange: 3/4 in, LF 3/4" FNPT UNION HARDWARE KIT, 3/4 in FNPT, 1 1/4 in NPSM, Union
ARMSTRONG Flange: 1 1/4 in, FLANGE CI 1.25" NPT F2+HWKIT, 1 1/4 in, Flange
ARMSTRONG
ARMSTRONG Flange: 1 1/4 in, FLANGE CI 1.25" NPT F2+HWKIT, 1 1/4 in, Flange
ARMSTRONG Flange: 561100LF-001, Compatible with OEM Part No. 32UN18, Flange
ARMSTRONG
ARMSTRONG Flange: 561100LF-001, Compatible with OEM Part No. 32UN18, Flange