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Brand: Spirax Sarco
Spirax Sarco BRV71 and BRV73 SG Iron Pressure Reducing Valves
Description
A compact direct acting reducing valve for steam
The Spirax Sarco BRV71 (screwed) and BRV73 (flanged) are SG iron bodied, direct acting pressure reducing valves designed for applications using steam. The downstream pressure is set with an adjustment handwheel acting on a control spring, and a stainless steel bellows senses the reduced pressure, so no external pilot line or power is needed. The datasheet also gives a compressed air capacity chart.
The valves are supplied with one of three colour-coded springs, identified by a disc on the handwheel: grey for 0.14 to 1.7 bar g (2.03 to 24.7 psi g), green for 1.40 to 4.0 bar g (20.3 to 58.0 psi g) and orange for 3.50 to 9.0 bar g (50.8 to 131 psi g). Where ranges overlap, the lower range should always be used to give better control.
Technical specifications
| Parameter | Specification |
|---|---|
| Model | Spirax Sarco BRV71 (screwed) and BRV73 (flanged), direct acting pressure reducing valve |
| Sizes | 1, 1-1/4, 1-1/2 and 2 in screwed BSP and NPT; DN25, DN32, DN40, DN50 flanged PN16, JIS 10 and ANSI 150 |
| Body | SG iron DIN 1693 GGG 40.3, ELNP coated; PN16 |
| Control spring ranges | Grey 0.14-1.7 bar g; green 1.40-4.0 bar g; orange 3.50-9.0 bar g |
| Max. allowable pressure | 16 bar g at 120 °C (232 psi g at 248 °F) |
| Max. operating pressure, saturated steam | 10 bar g (145 psi g) at 184 °C (363 °F) |
| Max. downstream reduced pressure | 9 bar g (131 psi g) |
| Max. differential pressure | 10 bar (145 psi) |
| Operating temperature | 0 to 184 °C (32 to 363 °F); minimum allowable -10 °C |
| Kv (full lift) | 9.3 (DN25), 11.1 (DN32), 15.7 (DN40), 16.2 (DN50) |
| Bellows and head | 316L stainless steel bellows; stainless steel head and pushrod |
| Test pressure | Cold hydraulic 24 bar g (348 psi g); 16 bar g with internals fitted |
Materials and pressure limits
The body is SG iron to DIN 1693 GGG 40.3, ELNP coated, and the spring housing is ELNP-coated aluminium. Wetted internals include a 316L stainless steel bellows, a stainless steel head and lower pushrod, a stainless steel strainer screen, a PTFE-graphite guide bush and EPDM O-rings. The control spring is silicon chrome, and the adjustment knob is mineral-filled nylon with a polypropylene printed cap.
The body design condition is PN16. The maximum operating pressure for saturated steam service is 10 bar g (145 psi g) at 184 °C (363 °F), the maximum downstream reduced pressure is 9 bar g and the maximum differential pressure is 10 bar. The minimum operating temperature is 0 °C, and for lower temperatures the manufacturer asks to be consulted. The pressure and temperature chart marks the region in which the product must not be used.
Sizing and installation
Sizing uses the steam and compressed air capacity chart: read the downstream pressure on the left, follow it to the upstream pressure curve and drop vertically to find the smallest size that passes the load. The example in the datasheet, 350 kg/h reducing from 8 to 6 bar, needs a DN25 valve. Kv values are 9.3 (DN25), 11.1 (DN32), 15.7 (DN40) and 16.2 (DN50) and should be used for safety valve sizing, with Cv (US) equal to Kv multiplied by 1.156.
The valve is installed in a horizontal pipeline with flow in the direction of the arrow on the body. Weights are about 4.4 kg for DN25 screwed (5.9 kg flanged) up to 4.75 kg screwed and 9.4 kg flanged for DN50. For a larger pilot-operated valve see the Spirax Sarco DP27 already listed in the catalogue, and for other steam valves browse Control Valves.
How the Spirax Sarco BRV71 works
The handwheel sets the load on the control spring. The spring pushes the valve open. The reduced steam pressure acts on the stainless steel bellows. The bellows push back against the spring and hold the downstream pressure steady.
Where the BRV71 is used
- Steam supply to process plant
- Steam to heat exchangers
- Steam to autoclaves and presses
- Steam to tracing lines
- Compressed air lines
Selection checklist for the BRV71
- Screwed BRV71 or flanged BRV73
- Line size
- Inlet pressure
- Reduced pressure
- Steam flow
- Spring colour
- Connection thread
- Valve capacity
Installation, commissioning and maintenance notes for the BRV71
Fit a strainer upstream of the valve. Fit a pressure gauge downstream. Drain the condensate ahead of the valve. Turn the handwheel slowly to the reduced pressure you need. Clean the strainer screen at regular intervals.
Requesting a quotation for the Spirax Sarco BRV71
Please send the size, the inlet pressure and the reduced pressure. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.
BRV71 valve type
It is a direct acting pressure reducing valve.
BRV71 connections
The BRV71 is screwed and the BRV73 is flanged.
BRV71 body material
The body is SG iron.
BRV71 pilot line
It needs no external pilot line or power.
BRV71 pressure setting
A handwheel sets the downstream pressure.
BRV71 grey spring
The grey spring covers 0.14 to 1.7 bar g.
BRV71 green spring
The green spring covers 1.40 to 4.0 bar g.
BRV71 orange spring
The orange spring covers 3.50 to 9.0 bar g.
BRV71 overlapping ranges
Use the lower range where two ranges overlap.
BRV71 screwed sizes
The sizes are 1, 1-1/4, 1-1/2 and 2 in.
BRV71 flanged sizes
The flanged sizes are DN25, DN32, DN40 and DN50.
BRV71 steam limit
The maximum operating pressure on saturated steam is 10 bar g.
BRV71 temperature range
The operating range is 0 to 184 degrees C.
BRV71 downstream limit
The maximum reduced pressure is 9 bar g.
BRV71 differential pressure
The maximum differential pressure is 10 bar.
BRV71 bellows
The bellows are 316L stainless steel.
BRV71 guide bush
The guide bush is PTFE-graphite.
BRV71 O-rings
The O-rings are EPDM.
BRV71 control spring
The spring is silicon chrome.
BRV71 spring housing
The housing is ELNP-coated aluminium.
BRV71 capacity
The Kv at full lift is 9.3 for DN25 and 16.2 for DN50.
Valve records for the BRV71
Record the set pressure, the spring colour and the service dates.
Choosing the right BRV71 spring
Choose the spring from the reduced pressure you need.
Documents and quotation
The technical information sheet TI-P210-01 is attached, including dimensions, spare parts and the how-to-order example. Specify the size and connection (BSP or NPT screwed for the BRV71; flanged PN16, JIS 10 or ANSI 150 for the BRV73), the spring colour and the required downstream pressure when requesting a quotation. Confirm that the steam supply is saturated and below 10 bar g before ordering.
Datasheets & Documents
- Datasheet Spirax Sarco BRV71 and BRV73 SG Iron Pressure Reducing Valves Technical Information TI-P210-01 (Issue 7, manufacturer) Download
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About brand
Steam is the specialty of Spirax Sarco: how to generate it cleanly, distribute it, control it and get the condensate back. The company dates from 1888 and is based in Cheltenham, United Kingdom. Seven Star LLC lists Spirax Sarco clean steam equipment, bellows sealed stop valves, steam traps and steam flowmeters, and sources them for process plants, hospitals and food factories in Oman.
Spirax Sarco products listed here
The listing includes these main groups, along with further steam traps, pressure reducing valves and filters:
- Clean steam and hygienic equipment: the CSG-HS clean steam generator, STERI-TROL clean service control valve, SRV66 sanitary pressure reducing valve, SVL488 clean service safety valve and the BT6-B balanced pressure thermostatic steam trap
- Isolation valves: BSA and BSAT bellows sealed stop valves, the BSA3HP high pressure version, A3S and A3SS valves and the DBB3 double block and bleed valve
- Steam metering: ILVA variable area flowmeter and the TVA and TFA target flowmeters
The STS17.2 steam-trapping station is a compact assembly for drain points.
Where Spirax Sarco steam equipment is used
Plant steam systems in refineries, chemical plants, laundries and food production use Spirax Sarco steam traps, stop valves and flowmeters for distribution and energy accounting. Clean steam products serve sterilizers, bioreactors, pharmaceutical water systems and food contact processes, where stainless steel wetted parts and documented surface finish are required. Requests from the GCC are often for a like-for-like trap or valve on an existing line.
Ordering Spirax Sarco parts: what we need
Give the product type (for example BSA3T or BT6-B), nominal size, end connection and its standard (flanged PN or ASME class, screwed, butt weld or sanitary clamp), body material and the operating pressure and temperature. For steam traps add the condensate load and differential pressure. For Spirax Sarco flowmeters send line size, steam pressure and the flow range, plus the display or flow computer required. On clean steam items, state the surface finish and the material certificates you need. A nameplate photo helps where the type is not known.
Browse Spirax Sarco products by category: Clean Steam, Globe Valve, Flowmeters.
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Frequently Asked Questions
What is the difference between the BRV71 and BRV73?
The BRV71 has screwed BSP or NPT connections and the BRV73 has flanged connections (PN16, JIS 10 and ANSI 150). Both are SG iron direct acting pressure reducing valves for steam.
Which spring ranges are available?
Grey 0.14 to 1.7 bar g, green 1.40 to 4.0 bar g and orange 3.50 to 9.0 bar g. Use the lower range where ranges overlap.
What is the maximum steam pressure?
10 bar g (145 psi g) for saturated steam service, with a maximum downstream reduced pressure of 9 bar g.
How should the valve be installed?
In a horizontal pipeline with flow in the direction shown by the arrow on the valve body.
Can it be used on compressed air?
The datasheet is written for steam applications and includes a compressed air capacity chart for sizing.
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