Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

This is an AMP page - Open full page! for all features.

the most efficient way to navigate the Engineering ToolBox!

Safety Valve Capacities in High Pressure Steam Systems

Sizing safety valves according boiler output power in high pressure systems (kW and Btu/hr)

Sponsored Links

The main purpose for a safety valve is

to prevent the pressure in a system to exceed certification pressure

Above certification pressure no one can guaranty the systems safety - and especially for a steam system with a very hot gas with a huge amount of latent heat the consequence with a failure can be dramatically.

The size of a safety valve depends primarily on the maximum boiler output and the operation pressure of the system. The safety valve must as minimum have the evacuation capacity of all the vapor the boiler can produce running at full power at the working (or certification) pressure.

for a higher pressure the steam is compressed and requires less volume and the size of the valve can be reduced
for a lower pressure the steam is expanded and requires more volume and the size of the valve is increased

The tables below can be used to select a typical safety valve in a high pressure system. Before the final design - always consult manufacturing documentation.

Steam Pressure 1000 kPa (10 bar) and 150 psi

Pipe Size		Capacity		Maximum Boiler Output
in	DN (mm)	kg/h	lb/h	kW	Btu/h
1/2	15	220	498	122	426 786
3/4	20	472	1 070	262	916 990
1	25	827	1 875	459	1 606 875
1 1/4	32	1 421	3 222	789	2 761 254
1 1/2	40	2 058	4 668	1 143	4 000 476
2	50	3 065	6 954	1 702	5 959 578
2 1/2	65	5 144	11 670	2 856	10 001 190
3	80	7 108	16 124	3 947	13 818 268
4	100	13 694	31 067	7 604	26 624 419

Note! The table above is based on steam with pressure 1000 kPa (10 bar) (or 150 psi in imperial units). Latent heat of saturated steam is 1999 kJ/kg (857 Btu/lb).

Steam Pressure 700 kPa (7 bar) and 100 psi

Pipe Size		Capacity		Maximum Boiler Output
in	DN (mm)	kg/h	lb/h	kW	Btu/h
1/2	15	159	346	90	304 480
3/4	20	342	743	194	653 840
1	25	599	1 302	340	1 145 760
1 1/4	32	1 030	2 238	585	1 969 440
1 1/2	40	1 792	3 242	1 018	2 852 960
2	50	2 222	4 827	1 263	4 247 760
2 1/2	65	3 730	8 101	2 120	7 128 880
3	80	5 153	11 193	2 929	9 849 840
4	100	9 929	21 566	5 643	18 978 080

Note! The table above is based on steam with pressure 700 kPa (7 bar) (or 100 psi in imperial units). Latent heat of saturated steam is 2046 kJ/kg (880 Btu/lb).

Steam Pressure 300 kPa (3 bar) and 50 psi

Pipe Size		Capacity		Maximum Boiler Output
in	DN (mm)	kg/h	lb/h	kW	Btu/h
1/2	15	79	193	47	176 016
3/4	20	169	414	100	377 568
1	25	296	726	175	662 112
1 1/4	32	509	1 248	302	1 138 176
1 1/2	40	737	1 807	437	1 647 984
2	50	1 099	2 695	651	2 457 840
2 1/2	65	1 844	4 522	1 093	4 124 064
3	80	2 547	6 248	1 509	5 698 176
4	100	4 907	12 038	2 907	10 978 656

Note! The table above is based on steam with pressure 300 kPa (3 bar) (or 50 psi in imperial units). Latent heat of saturated steam is 2133 kJ/kg (912 Btu/lb).

1 N/m² = 1 Pa = 1.4504 x 10^-4 lb/in² (psi) = 1x10^-5 bar

Sponsored Links

Related Topics

Control Valves and Equipment - Sizing and dimensions of control valves & equipment in steam and condensate systems.

Related Documents

API 6D Valves - Pressure Ratings vs. Temperature - Temperature and pressure ratings for valves according API 6D.
ASME - International Boiler and Pressure Vessel Code - The International Boiler and Pressure Vessel Code safety rules governing design, fabrication, and inspection of boilers and pressure vessels, and nuclear power plant components during construction.
ASTM A216 Valves - Pressure Ratings vs. Temperature - Pressure and temperature ratings for cast carbon steel valves.
Boilers - Classification - Classification of boilers according the ASME Boiler and Pressure Vessel Code.
Factors of Safety - Factors of Safety - FOS - are important in engineering designs.
Heating Systems - Safety Valves Size vs. Boiler Power - Safety valves with boilers ranging 275 to 1500 kW.
Low Pressure Steam Safety Valves - Capacities - Sizing safety valves after boiler output power in low pressure systems (kW and Btu/hr).
Pilot Operated Safety Valves in Liquid Systems - Calculate pilot operated relief valves in liquid systems.
Reliability of Machine Components - Mean Time Between Failure - MTB and reliability of machine components and systems.
Safety Signals - Recommended Colors - American National Standards Institutes schedule for safety colors marking physical hazards.
Safety Valve Standards - The most common used safety valve standards in Germany, UK, USA, France, Japan, Australia and Europe.
Safety Valves in Saturated Steam Systems - Calculate safety valves in saturated steam systems
Spring Operated Safety Valves in Liquid Systems - Calculate spring operated relief valves in liquid systems.

Sponsored Links

Share

Search Engineering ToolBox

the most efficient way to navigate the Engineering ToolBox!

SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

About Engineering ToolBox!

Contact - Citation - Copyrights - Advertising - Warranty and Liability

Privacy

We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.

Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

Google use cookies for serving our ads and handling visitor statistics. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected.

AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information.

Advertise in the ToolBox

If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. You can target the Engineering ToolBox by using AdWords Managed Placements.