Spirax Sarco SRV2S Stainless Steel Pressure Reducing Valve

The Spirax Sarco SRV2S is a compact, direct acting pressure reducing valve with all wetted parts in 316L stainless steel, intended for steam and for gases such as compressed air. A stainless steel bellows senses the downstream pressure and positions the valve against an adjustable spring, so the outlet pressure holds close to the set point without an external pilot or control signal. It suits clean steam users, process skids, sterilisers and utility branches where a small stainless valve is needed.

Technical specifications

Three springs, one valve

The valve is supplied with one of three colour-coded springs, identified by a disc on the adjustment handwheel: grey for downstream pressures of 0.14 to 1.7 bar g, green for 1.4 to 4.0 bar g and orange for 3.5 to 8.6 bar g. Where ranges overlap, the data sheet advises using the lower range for better control. The handwheel is covered by a tamper-proof pin option, and the maximum outlet pressure the valve will control is 8.6 bar g (125 psi g).

The design is direct acting with a bellows, not a diaphragm, so it avoids elastomeric diaphragms in steam service and can be used on gases as well.

Sizing and capacity

Flow coefficient Kv is 1.5 for DN15, 2.5 for DN20 and 3.0 for DN25; the data sheet gives conversions Cv (UK) = Kv x 0.96 and Cv (US) = Kv x 1.15. Capacity charts show steam in kg/h and compressed air in dm3/s as a function of upstream and downstream pressure, with a worked example: reducing from 8 to 6 bar to pass 120 kg/h calls for a 1/2 in. valve. The maximum recommended turndown at maximum flow is 10:1, and the maximum differential pressure across the valve is 19 bar.

Capacities for safety valve sizing are given too, which is needed when a relief valve has to protect equipment downstream of the reducing station.

Installation guidance

The data sheet limits the product to 19 bar g saturated steam and 212 C with a minimum temperature of 0 C. Use a strainer ahead of the valve if one is not built in (the valve has an internal screen) and install a safety valve downstream sized for the full flow of the PRV. For steam, give the valve drain points upstream to keep condensate away from the seat and use a pressure gauge on the downstream side to set the spring.

Order by model, size, connection and spring range, for example a DN15 SRV2S with PN25 flanges and a green spring. The data sheet gives screwed ½ in. dimension A of 83 mm and weight 1.48 kg, against 3.1 kg for the PN25 flanged DN15.

Documents and quotation

The official Spirax Sarco technical information sheet TI-P186-05 is attached to this page; it carries the spring ranges, pressure-temperature limits, materials, capacity chart and dimensions summarised above. Seven Star LLC is an independent supplier in Muscat. To request a quotation for SRV2S, send the model, size, end connection, any certification you need under EN 10204 and the quantity so the request can be matched to the data sheet before we reply.

Check the code, size and end connection against the catalog table before purchase, since variants with similar numbers exist. Related items: product category.