Spirax Sarco DCV1 Bronze Wafer Disc Check Valve

A spring-closed wafer check for steam, condensate and hot water

The Spirax Sarco DCV1 disc check valve is a wafer pattern valve designed to be sandwiched between flanges. It suits process lines, hot water systems and steam and condensate systems, with face-to-face dimensions conforming to EN 558 part 1, series 49. The valve is opened by fluid pressure and closed by a spring as soon as flow ceases and before reverse flow occurs.

The standard valve has a metal-to-metal seat for steam. For oil, air, gas and water duties, soft seats are an option: Viton for oil, air and gas, and EPDM for water. Heavy duty springs, with a 700 mbar opening pressure up to DN65, are available for boiler feed applications.

Technical specifications

Materials, limits and shut-off class

The body is bronze (WS 2.1050) and the disc, spring retainer and springs are austenitic stainless steel (disc ASTM A276 316, spring BS 2056 316 S42). The body design condition for saturated steam is PN16: maximum allowable pressure 16 bar g at 120 °C, maximum allowable temperature 260 °C at 7 bar g and minimum -198 °C. The maximum operating pressure for saturated steam service is 13.2 bar g at 196 °C. These figures apply to the metal-to-metal seat; with a Viton seat the limits are -25 to +205 °C and with EPDM -40 to +120 °C.

Standard shut-off conforms to EN 12266-1 rate E, rate D is available on request, and soft-seated versions meet rate A while a differential pressure exists. The valve is available with a manufacturer typical test report.

Fitting range and selection

Sizes are DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80 and DN100, fitting between BS 10 Tables E and H, EN 1092 PN6 to PN40 and JIS 5 to JIS 20 flanges, with exceptions: DN40, DN50, DN80 and DN100 do not fit between JIS 5 flanges, and DN65 and DN80 do not fit between BS 10 E flanges. Kv values rise from 4.4 at DN15 to 113 at DN100; opening pressures with zero flow are about 20 to 33 mbar depending on size and spring.

Wafer check valves are not suitable where heavily pulsating flow exists, such as close to a compressor. Where the lowest opening pressure is required, valves without springs can be installed in vertical pipes with bottom-to-top flow. For other check valve styles in the same family, browse Fittings & Valves.

Key features

• Short wafer body to EN 558 part 1, series 49, saving space and weight compared with flanged swing checks.
• Spring closing before reverse flow begins, which reduces water hammer and allows installation in any plane when the spring is fitted.
• Bronze body with stainless steel disc and springs, suited to steam, condensate and hot water.
• Fits a broad set of flange standards, including EN 1092 PN6 to PN40, BS 10 and JIS.
• Soft seat options in Viton or EPDM for tighter shut-off on liquids and gases.
• Heavy duty spring option for boiler feed service.

Typical uses

• Condensate return lines after steam traps and on pumped condensate discharges.
• Boiler feed pump discharges, using the heavy duty spring.
• Hot water circulation in buildings, hospitals and hotels.
• Compressed air and process gas lines with a Viton seat.
• Cooling and process water lines with an EPDM seat.

Choosing seat and spring

Installation and maintenance

Install the valve with the flow arrow pointing in the direction of flow and centre it carefully between the flanges so the disc does not rub on the gasket or bolts. Place it at least a few pipe diameters away from pumps, elbows and control valves where turbulence or pulsation can make the disc chatter. In Oman and GCC facilities, these valves are frequently used on hotel and hospital hot water and steam systems and on industrial laundries and food plants. Water hardness in some areas can cause scale build-up on the seat, so include check valves in descaling and inspection routines and replace soft seats when they harden.

What to include in your RFQ

• Size (DN15 to DN100) and quantity
• Fluid, maximum pressure and temperature
• Seat material: metal, Viton or EPDM
• Spring: standard, heavy duty or none
• Flange standard and rating of the mating flanges, so fit can be confirmed against the listed exceptions
• Pipe orientation and flow direction
• Required shut-off rate and whether a typical test report is needed

Because the DCV1 is a wafer valve, longer studs are needed than for a simple flange joint; include them in the order if your site does not stock suitable bolting. Where the line carries pulsating flow, for example close to a reciprocating compressor, discuss a different check valve type before ordering.

Documents and quotation

The technical information sheet TI-P134-05 is attached with dimensions and weights, from 60 mm length and 0.13 kg at DN15 to 184 mm and 3.81 kg at DN100. State the size, fluid, seat material, spring type and flange standard when requesting a quotation, and confirm the installation orientation.