Brand: Swagelok

Swagelok SS-20KF4 Soft-Seat Needle Valve, 0.09 Cv, 1/4 in. FNPT

Name: Swagelok SS-20KF4 Soft-Seat Needle Valve | Seven Star LLC
Brand: Swagelok
SKU: SS-20KF4

Description

The Swagelok SS-20KF4 is the soft-seat member of the 20 series needle valves. Its stem carries a PCTFE tip that seats into the body for tight shutoff of small gas and liquid flows, and the 20 series body is rated to 6000 psig (413 bar), higher than the 5000 psig of the 1 series. It has 1/4 in. female NPT ports, a small 0.080 in. orifice and a flow coefficient of 0.09.

Technical specifications

Parameter	Specification
Part number	SS-20KF4
Description	Integral-bonnet needle valve, soft-seat stem with PCTFE tip, straight pattern
Series	20
Body material	316 stainless steel
Connections	1/4 in. female NPT x 1/4 in. female NPT
Flow coefficient Cv	0.09
Orifice	0.080 in. (2.0 mm)
Stem tip	PCTFE
Handle	Anodised aluminium knob (20K series)
Working pressure at 100 F (37 C)	6000 psig (413 bar)
Catalog dimension A	1.88 in. (47.8 mm)
Temperature limit with PCTFE tip	200 F (93 C) maximum, per catalog
Low emissions	Certified, as listed on the Swagelok data page

Soft seat for tight shutoff

A metal-to-metal needle seat can pass a small leak when closed. A soft seat trades temperature range for tightness: the PCTFE tip deforms slightly against the seat and gives bubble-tight closure on clean fluids. The catalog is explicit about the cost, limiting valves with the PCTFE tip to 200 F (93 C), even though the metal-tip valves are rated to higher temperature. Choose SS-20KF4 for ambient or warm service where tight closure matters and the line is clean; choose a vee stem version such as SS-20VS4 if temperature is high or the fluid could attack PCTFE.

With a 0.080 in. orifice and a Cv of 0.09, flow capacity is small, which is consistent with analyser, sample and calibration gas service.

The 20 series body

The 20 and 26 series share a different body construction from the O, 1 and 18 series: the body is machined from 316 stainless bar, with a 6000 psig rating at ambient temperature that falls to 5160 psig at 200 F, 4660 at 300 F and 4130 at 450 F. The 20K version has a knob handle in anodised aluminium; 20V versions have a stainless steel bar handle. Live-loaded two-piece chevron packing, a feature of the whole range, is fully supported to reduce the need for adjustment.

Each valve is nitrogen-tested at 1000 psig and the catalog lists a maximum seat leak rate of 0.1 std cm3/min; the low-emissions certification to API 624 is marked on the data page.

Ordering, installation and care

In SS-20KF4, SS is stainless steel, 20 is the series, K is the soft-seat stem with PCTFE tip, F is female NPT and 4 is the 1/4 in. size. SS-20KM4 is the male NPT version and SS-20KM4-F4 a male by female. Use sealant on the tapered threads, keep the handle clear of the packing nut, and do not over-tighten the closed stem: a soft tip is damaged by excessive closing torque and will no longer give tight shutoff.

Install with a filter ahead of the valve in dirty service, because particles lodged on a PCTFE tip also cause leakage. Quote the full code when ordering.

Documents and quotation

The attached Swagelok integral-bonnet needle valves O, 1, 18, 20 and 26 series catalog MS-01-164 (EN) is the reference for every value on this page. Seven Star LLC, an independent supplier in Muscat, quotes SS-20KF4 against the exact code; please add the quantity and any special requirement.

Verify the order code and connection standard against your specification and the catalog before ordering. Related items: product category.

Datasheets & Documents

Catalog Swagelok integral-bonnet needle valves O, 1, 18, 20 and 26 series catalog MS-01-164 (EN) Download

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About brand

Two-ferrule tube fittings made Swagelok a familiar name on instrument air headers, impulse lines and analyzer sample systems. The company has made fluid system components since 1947 and is based in Solon, USA. Seven Star LLC sources and supplies Swagelok tube fittings, ball valves, needle valves, quick-connects, face seal fittings and pressure regulators for plants in Oman, checking every ordering number against the manufacturer's catalog before an offer is made.

Swagelok product families listed here

The items on this page cover the small-bore components an instrument technician handles most often. Swagelok tube fittings join metric and fractional tubing without threading or welding. Swagelok ball valves are represented by the 40 series, the 40G series one-piece instrumentation ball valve (for example SS-43GS4) and the three-way pattern listed as 40GX. The SS-1RS4 is an integral bonnet needle valve from the 1 series. VCR metal gasket face seal fittings serve high-purity and vacuum lines, QC series quick-connects are used where lines are coupled and uncoupled often, and the KPR series is a pressure-reducing regulator.

Where Swagelok components are used

Typical duties are transmitter hook-ups, manifolds and impulse tubing, analyzer shelters and sample conditioning panels, chemical injection skids, gas cylinder panels in laboratories, and test benches. In oil and gas service across the GCC, the usual questions are material grade, pressure rating at temperature and, for sour service, whether the manufacturer offers the item to NACE MR0175 requirements.

Ordering Swagelok fittings and valves: what we need

A Swagelok ordering number carries most of the specification. In SS-43GS4, SS is 316 stainless steel, 43G identifies the valve series and size, and S4 is a 1/4 in. Swagelok tube fitting end connection. Send the complete ordering number including any suffix for handle, seat or cleaning option. If you do not have it, give us the tube outside diameter and wall thickness, body material, end connections on each port, working pressure and temperature, and the fluid. For a KPR regulator we also need inlet pressure, the outlet control range and the port configuration.

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