Brand: Swagelok

Swagelok SS-4C4-1 Poppet Check Valve, 1/4 in. FNPT, 1 psig

Name: Swagelok SS-4C4-1 Check Valve 1/4 in. FNPT | Seven Star LLC
Brand: Swagelok
SKU: SS-4C4-1

Description

The Swagelok SS-4C4-1 is a fixed-pressure poppet check valve with 1/4 in. female NPT ports and a 1 psig (0.07 bar) cracking pressure. The female thread lets the valve screw onto male nipples or fittings in an NPT pipe system, where the tube-fitting version SS-4C-1 would need tubing. The body is 316 stainless steel, the seal a fluorocarbon FKM O-ring, and the rating is 3000 psig (206 bar) at room temperature.

Technical specifications

Parameter	Specification
Part number	SS-4C4-1
Description	Poppet check valve, fixed cracking pressure
Series	C
Body material	316 stainless steel
Connections	1/4 in. female NPT x 1/4 in. female NPT
Nominal cracking pressure	1 psig (0.07 bar)
Flow coefficient Cv	0.47
O-ring material	Fluorocarbon FKM
Working pressure	3000 psig (206 bar) at 100 F (37 C)
Length A	2.15 in. (54.6 mm)
Hex size	3/4 in.
Cleaning	Standard cleaning and packaging SC-10

Female NPT version of the C series

The C series catalog lists the same check valve with several end connections. In the 1/4 in. size the female NPT code SS-4C4- measures 2.15 in. (54.6 mm) with a 3/4 in. hex, a little shorter than the 2.35 in. tube fitting body but with a larger hex because it must take wrench torque on a thread. Flow direction is marked with an arrow and the valve must be installed accordingly.

Female tapered threads are sensitive to over-tightening of the male part, so snug it and then add the turns recommended for the thread sealant you use.

Cracking pressure and use

A 1 psig nominal cracking pressure, with a cracking range up to 4 psi, makes the valve open with very little differential pressure. It is for low-pressure gas lines, vents and sample systems where a stray backflow would contaminate an analyser. For higher cracking pressures the C series has 10 and 25 psig versions, and the adjustable CA series covers 3 to 600 psig in four ranges. A check valve is a flow-direction device and must never be used as a code safety relief device.

The data page lists no optional testing; special testing can be added by suffix.

Ordering

SS is 316 stainless steel, 4C the 1/4 in. C series, 4 the female NPT end and 1 the 1 psig cracking pressure. SS-4C2-1 is the male NPT version, SS-4C-1 has tube fitting ends and SS-4C1-1 has male NPT on one side and tube fitting on the other. Add an alternate O-ring designator if the fluid is not compatible with FKM.

Quote the exact code with the connection digit, since the 2, 4 and S versions have different lengths.

Documents and quotation

This page links the official Swagelok check valves C, CA, CH, CP and CPA series catalog MS-01-176 (EN, rev. N), which holds the ordering data, ratings and materials behind the figures above. Seven Star LLC is an independent supplier in Muscat; for a quotation on SS-4C4-1, tell us the quantity and any option you need, such as handle colour, seal material or special cleaning.

Confirm the full order code, including any suffix, with your drawing before you order; similar codes are easy to mix up. Related items: product category.

Datasheets & Documents

Catalog Swagelok check valves C, CA, CH, CP and CPA series catalog MS-01-176 (EN, rev. N) Download

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About brand

Swagelok is the American maker of tube fittings and small-bore valves, best known for its two-ferrule compression tube fitting. Fred A. Lennon and Cullen B. Crawford founded it in Cleveland, Ohio, in July 1947 as Crawford Fitting Company to make that fitting. Lennon bought the whole business and the patent in 1948, and the company has been based in Solon, Ohio, since the mid-1960s.

Seven Star LLC is an independent supplier in Muscat. We list Swagelok tube fittings, needle, ball, check, relief and metering valves, filters, regulators and sample cylinders, and supply them for instrument tubing and analyser systems in Oman and the GCC by exact part number.

Swagelok company profile

Established	July 1947, Cleveland, Ohio, as Crawford Fitting Company
Founders	Fred A. Lennon and Cullen B. Crawford; Lennon bought out Crawford in 1948
Headquarters	Solon, Ohio, since the mid-1960s
Product families	Tube fittings and adapters, face seal fittings, needle, ball, plug, check, relief and diaphragm valves, filters, regulators, quick-connects, sample cylinders and hoses

Milestones

1947: Fred A. Lennon and Cullen B. Crawford found Crawford Fitting Company in Cleveland in July.
1948: Lennon buys out Crawford.
Mid-1960s: Headquarters move to Solon, Ohio.

Swagelok products we list

Family	Models	Typical use
Tube fittings	Overview, SS-810-6 union, SS-810-3 tee, SS-810-9 elbow, SS-810-4 cross, SS-810-1-8 male connector, SS-810-7-8 female connector, SS-810-61 bulkhead, SS-12M0-6 metric union, VCR face seal	Leak-tight connections on instrument and process tubing
Needle and metering valves	SS-1RS4, SS-1RF4, SS-18RF6, SS-6NBS6, SS-20VS4, SS-4MG	Isolation and fine flow adjustment on instrument lines and sample systems
Ball and plug valves	40G, 40GX 3-way, 60 Series, 83 Series, P4T plug	Quick quarter-turn shut-off and switching
Check, relief and sealed valves	SS-4C-1, CH, R3A, RL3, SS-4BK bellows, SS-DLS4 diaphragm	Backflow prevention, overpressure relief and leak-free sealing for toxic or high-purity media
Filters, regulators, sampling	SS-4F-2, SS-4TF-7, KPR regulator, sample cylinders, QC quick-connects	Analyser sample conditioning and gas or liquid sampling

A Swagelok part number can be read directly. In SS-810-6, "SS" is 316 stainless steel, "810" means a 1/2 in. tube fitting (8 sixteenths of an inch, 10 series), and "-6" is a union. A suffix such as "-8" adds a 1/2 in. NPT end, and "M0" marks metric tube, as in SS-12M0-6 for 12 mm. Tube fittings must be made up the same way every time: finger-tight, then 1 1/4 turns for most sizes. A gap inspection gauge confirms the fitting has been pulled up.

Where Swagelok products are used

In Oman and the GCC, Swagelok fittings and valves are used on instrument impulse lines, analyser sample systems, hydraulic and pneumatic control tubing, chemical injection and gas sampling in oil and gas, refining, petrochemical, power and laboratory installations.

Ordering Swagelok products: what we need

Send the full Swagelok part number (for example SS-810-6 or SS-1RS4), the material, and the tube size in inches or millimetres. For valves, add the end connections and any options. For sample cylinders, add the volume, pressure rating and end configuration.

Facts checked against Swagelok company history, October 2026.

Browse Swagelok products by category: Pipes & Fittings, Regulators, Fittings & Valves.

FAQ

Questions about the Swagelok SS-4C4-1 Poppet Check Valve, 1/4 in. FNPT,

Answers from our engineering team on installation, compatibility and integration.

01What ports does SS-4C4-1 have?

1/4 in. female NPT at both ends.

02What is the cracking pressure?

1 psig (0.07 bar).

03What is the pressure rating?

3000 psig (206 bar) at 100 F (37 C).

04How long is it?

The catalog lists 2.15 in. (54.6 mm) with a 3/4 in. hex.

05Can it be used as a relief valve?

No. Swagelok check valves are not code safety relief devices.