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Instrument & Compression Fittings
Ensure dependable, leak-tight connections with our high-quality instrument and compression fittings. Designed for precision, durability, and corrosion resistance, these fittings provide reliable performance in critical instrumentation and fluid system applications. Our selection includes tube fittings, pipe fittings, adapters, and connectors, available in a variety of sizes, materials, and pressure ratings to meet your specific needs. Ideal for oil and gas, chemical processing, power generation, water treatment, and manufacturing, these fittings help maintain system integrity and reduce downtime. With rugged construction, easy installation, and trusted-brand reliability, our instrument and compression fittings deliver long service life, superior sealing, and consistent performance in demanding environments.
Filters 508 Results
508 items
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The Dwyer - BRLK-18-18 is a Compression Fitting featuring 1/8 " NPT Male, Brass, RoHS Compliant, 30 mm L, and Heavy Duty Construction. Part of the OMEGALOK Series. Sold individually.
$14.21
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-18-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, 316 Stainless Steel, and 1/8 " (OD). Part of the SSLK Series. Sold individually.
$31.56
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - SSLK-14-14 is an Adaptor featuring Compression Fitting, 1/4 " NPT Male, Straight, 316 Stainless Steel, and 1/4 " (OD). Part of the SSLK Series. Sold individually.
$29.89
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - SSLK-116-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, 316 Stainless Steel, and 1/16 " (OD). Part of the SSLK Series. Sold individually.
$45.88
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - BRLK-316-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, Brass, and 3/16 " (OD). Part of the BRLK Series. Sold individually.
$14.57
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-18-14 is an Adaptor featuring Compression Fitting, 1/4 " NPT Male, Straight, 316 Stainless Steel, and 1/8 " (OD). Part of the SSLK Series. Sold individually.
$35.54
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - SSLK-14-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, 316 Stainless Steel, and 1/4 " (OD). Part of the SSLK Series. Sold individually.
$30.62
Should ship between 12 Dec and 19 Dec
Subject to factory lead times
The Dwyer - BRLK-14-14 is an Adaptor featuring Compression Fitting, 1/4 " NPT Male, Straight, Brass, and 1/4 " (OD). Part of the BRLK Series. Sold individually.
$14.21
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-116-116 is an Adaptor featuring Compression Fitting, 1/16 " NPT Male, Straight, 316 Stainless Steel, and 1/16 " (OD). Part of the SSLK Series. Sold individually.
$46.99
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - BRLK-18-14 is a Compression Fitting featuring 1/4 " NPT Male, Brass, RoHS Compliant, 44.2 mm L, and Heavy Duty Construction. Part of the OMEGALOK Series. Sold individually.
$14.22
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - BRLK-316-14 is a Compression Fitting featuring 1/4 " NPT Male, Brass, RoHS Compliant, 46 mm L, and Heavy Duty Construction. Part of the OMEGALOK Series. Sold individually.
$15.02
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-316-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, 316 Stainless Steel, and 3/16 " (OD). Part of the SSLK Series. Sold individually.
$31.57
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-316-14 is an Adaptor featuring Compression Fitting, 1/4 " NPT Male, Straight, 316 Stainless Steel, and 3/16 " (OD). Part of the SSLK Series. Sold individually.
$37.54
Should ship between 12 Dec and 19 Dec
Subject to factory lead times
The Dwyer - BRLK-M15-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, Brass, and 1.5 mm (OD). Part of the BRLK Series. Sold individually.
$21.31
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - SS-FER-1/16 is a Replacement Ferrule featuring Cap/Plug, 316 Stainless Steel, and 1/16 " (OD). Part of the SS-FER Series. Sold as a pack of 10.
$160.18
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - BRLK-116-18 is a Compression Fitting featuring 1/8 " NPT Male, Brass, RoHS Compliant, 26.2 mm L, and Heavy Duty Construction. Part of the OMEGALOK Series. Sold individually.
$24.71
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-14-12 is an Adaptor featuring Compression Fitting, 1/2 " NPT Male, Straight, 316 Stainless Steel, and 1/4 " (OD). Part of the SSLK Series. Sold individually.
$65.06
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - B-FER-1/16 is a Replacement Ferrule featuring Cap/Plug, Brass, and 1/16 " (OD). Part of the B-FER Series. Sold as a pack of 10.
$62.58
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - T-FER-1/8 is a Replacement Ferrule featuring Cap/Plug, PTFE, and 1/8 " (OD). Part of the T-FER Series. Sold as a pack of 10.
$145.84
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - T-FER-1/16 is a Replacement Ferrule featuring Cap/Plug, PTFE, and 1/16 " (OD). Part of the T-FER Series. Sold as a pack of 10.
$224.69
Should ship between 12 Dec and 19 Dec
Subject to factory lead times
The Dwyer - BRLK-38-38 is an Adaptor featuring Compression Fitting, 3/8 " NPT Male, Straight, Brass, and 3/8 " (OD). Part of the BRLK Series. Sold individually.
$28.55
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - BRLK-M30-12P is an Adaptor featuring Compression Fitting, 1/2 " BSPP Male, Straight, Brass, and 3 mm (OD). Part of the BRLK Series. Sold individually.
$29.82
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - BRLK-M60-12 is a Compression Fitting featuring 1/2 " NPT Male, Brass, RoHS Compliant, 6 mm L, and Heavy Duty Construction. Part of the OMEGALOK Series. Sold individually.
$52.57
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - SS-FER-1/4 is a Replacement Ferrule featuring Cap/Plug, 316 Stainless Steel, and 1/4 " (OD). Part of the SS-FER Series. Sold as a pack of 10.
$83.40
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - BRLK-18-18 is a Compression Fitting featuring 1/8 " NPT Male, Brass, RoHS Compliant, 30 mm L, and Heavy Duty Construction. Part of the OMEGALOK Series. Sold individually.
$14.21
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-18-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, 316 Stainless Steel, and 1/8 " (OD). Part of the SSLK Series. Sold individually.
$31.56
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - SSLK-14-14 is an Adaptor featuring Compression Fitting, 1/4 " NPT Male, Straight, 316 Stainless Steel, and 1/4 " (OD). Part of the SSLK Series. Sold individually.
$29.89
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - SSLK-116-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, 316 Stainless Steel, and 1/16 " (OD). Part of the SSLK Series. Sold individually.
$45.88
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - BRLK-316-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, Brass, and 3/16 " (OD). Part of the BRLK Series. Sold individually.
$14.57
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-18-14 is an Adaptor featuring Compression Fitting, 1/4 " NPT Male, Straight, 316 Stainless Steel, and 1/8 " (OD). Part of the SSLK Series. Sold individually.
$35.54
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - SSLK-14-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, 316 Stainless Steel, and 1/4 " (OD). Part of the SSLK Series. Sold individually.
$30.62
Should ship between 12 Dec and 19 Dec
Subject to factory lead times
The Dwyer - BRLK-14-14 is an Adaptor featuring Compression Fitting, 1/4 " NPT Male, Straight, Brass, and 1/4 " (OD). Part of the BRLK Series. Sold individually.
$14.21
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-116-116 is an Adaptor featuring Compression Fitting, 1/16 " NPT Male, Straight, 316 Stainless Steel, and 1/16 " (OD). Part of the SSLK Series. Sold individually.
$46.99
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - BRLK-18-14 is a Compression Fitting featuring 1/4 " NPT Male, Brass, RoHS Compliant, 44.2 mm L, and Heavy Duty Construction. Part of the OMEGALOK Series. Sold individually.
$14.22
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - BRLK-316-14 is a Compression Fitting featuring 1/4 " NPT Male, Brass, RoHS Compliant, 46 mm L, and Heavy Duty Construction. Part of the OMEGALOK Series. Sold individually.
$15.02
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-316-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, 316 Stainless Steel, and 3/16 " (OD). Part of the SSLK Series. Sold individually.
$31.57
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-316-14 is an Adaptor featuring Compression Fitting, 1/4 " NPT Male, Straight, 316 Stainless Steel, and 3/16 " (OD). Part of the SSLK Series. Sold individually.
$37.54
Should ship between 12 Dec and 19 Dec
Subject to factory lead times
The Dwyer - BRLK-M15-18 is an Adaptor featuring Compression Fitting, 1/8 " NPT Male, Straight, Brass, and 1.5 mm (OD). Part of the BRLK Series. Sold individually.
$21.31
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - SS-FER-1/16 is a Replacement Ferrule featuring Cap/Plug, 316 Stainless Steel, and 1/16 " (OD). Part of the SS-FER Series. Sold as a pack of 10.
$160.18
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - BRLK-116-18 is a Compression Fitting featuring 1/8 " NPT Male, Brass, RoHS Compliant, 26.2 mm L, and Heavy Duty Construction. Part of the OMEGALOK Series. Sold individually.
$24.71
Should ship between 14 Nov and 21 Nov
Subject to factory lead times
The Dwyer - SSLK-14-12 is an Adaptor featuring Compression Fitting, 1/2 " NPT Male, Straight, 316 Stainless Steel, and 1/4 " (OD). Part of the SSLK Series. Sold individually.
$65.06
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - B-FER-1/16 is a Replacement Ferrule featuring Cap/Plug, Brass, and 1/16 " (OD). Part of the B-FER Series. Sold as a pack of 10.
$62.58
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - T-FER-1/8 is a Replacement Ferrule featuring Cap/Plug, PTFE, and 1/8 " (OD). Part of the T-FER Series. Sold as a pack of 10.
$145.84
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - T-FER-1/16 is a Replacement Ferrule featuring Cap/Plug, PTFE, and 1/16 " (OD). Part of the T-FER Series. Sold as a pack of 10.
$224.69
Should ship between 12 Dec and 19 Dec
Subject to factory lead times
The Dwyer - BRLK-38-38 is an Adaptor featuring Compression Fitting, 3/8 " NPT Male, Straight, Brass, and 3/8 " (OD). Part of the BRLK Series. Sold individually.
$28.55
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - BRLK-M30-12P is an Adaptor featuring Compression Fitting, 1/2 " BSPP Male, Straight, Brass, and 3 mm (OD). Part of the BRLK Series. Sold individually.
$29.82
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - BRLK-M60-12 is a Compression Fitting featuring 1/2 " NPT Male, Brass, RoHS Compliant, 6 mm L, and Heavy Duty Construction. Part of the OMEGALOK Series. Sold individually.
$52.57
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
The Dwyer - SS-FER-1/4 is a Replacement Ferrule featuring Cap/Plug, 316 Stainless Steel, and 1/4 " (OD). Part of the SS-FER Series. Sold as a pack of 10.
$83.40
Should ship between 21 Nov and 28 Nov
Subject to factory lead times
FAQ
- Instrument fittings is the broader category (tube fittings, manifolds, valves, and adapters used for instrument and analyzer connections). Compression fittings are one specific style of instrument fitting where a nut compresses a ferrule onto the tubing to make a seal. All compression fittings are instrument fittings; not all instrument fittings are compression style.
- Two metal ferrules (front and back) sit on the tubing inside the fitting body. Tighten the nut and the front ferrule bites into the tube to make a leak-tight seal, while the back ferrule grips the tube to hold it in place. Properly assembled (1-1/4 turns past finger-tight on first assembly), the joint handles full pressure and routine vibration with no leaks. The two-ferrule design is the industry standard for instrument tubing.
- Stainless 316 for general industrial and corrosive service. Stainless 304 for clean utility work. Carbon steel for non-corrosive, lower-cost installations. Copper and brass for pneumatic and water. PFA, PTFE, and PVDF for aggressive chemicals at moderate pressure. Match the tubing material to the fitting material whenever possible; mixing harder fittings on softer tubes (or vice versa) breaks the ferrule grip.
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About NISCO Inc.
NISCO offers a wide range of pressure gauges & instruments, diaphragm seals, thermometers, valves, and flow control products to the industrial and commercial marketplaces, as well as other resellers like ourselves. We can also provide other value-added services such as gauge repair, NIST traceable calibration, diaphragm seal assembly, and valve automation. NISCO takes pride in providing extensive product knowledge, helpful customer service, and market competitive pricing to help fit whatever need you may have because it is our goal to be regarded by our customers as the best supplier of pressure, temperature, and flow control products.