At left is the Hoffman No. 41 is a steam vent . The mounting method of a vent varies and is a reason for making sure you have the right replacement steam vent.
The information in this article will assist you in selecting the proper replacement steam vent for your 1 or 2 pipe steam heat system.
Watch out: If the radiator continually makes noises (whistling or wheezing) at the steam vent, there is a problem that needs to be fixed: a bad steam vent, steam piping problem, steam pressure set too high, or boiler oversized for the heating distribution system.
Watch out: Be sure your steam heating system and its controls are properly adjusted - excessive steam pressure can be dangerous.
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Summary of Types of Steam Vents on 1 & 2 Pipe Steam Systems
The following tables are adapted from product literature provided by Emersonswan.com, a provider of Vent-Rite steam vents for radiators, convectors, steam risers, main steam vents and vents for unit heaters.
Table of Non-Vacuum Vents & Their Applications & Substitution Part Numbers
Vent-Rite, Dole, & Hoffman Steam Vents 1
1. Adapted from "Air Valve for Steam Systems", Emerson Swan (Vent-Rite), Vent-Rite Valve Corporation:
1875 Dewey Ave. Benton Harbor, MI 49022 TEL: (269) 925-8818 FAX: (269) 925-7888 retrieved 2/28/2014, original source www.emersonswan.com/ckfinder/userfiles/ files/Vent-Rite%20Literature%281%29.pdf
2. Operating pressure drop ("drop away") is the maximum pressure at which the vent will continue to open and close due to the change of temperature.
The vent may be used with slightly higher pressure provided it drops below the operating pressure between each firing cycle.
Steam Vent Product Cross Reference
Steam Vent Cross Reference / Substitution Chart
Eaton / Dole
Hoffman
Vent-Rite
1A
1A
1
4
45
35
3A
41
31
3B
43
33
3C
45
75
5
45
77
55
74
57
1933
40
11
Notes to the table above:
Watch out: be sure to review the manufacturer's specific details before attempting to swap steam vents. Other manufacturers will have additional steam vent cross-reference charts; do not attempt to remove a steam vent if you are not properly trained as you could be badly burned or injured.
Some of these steam vents work on either 1-pipe or 2-pipe steam systems while some others such as the Dole (now Eaton Steam Vents) 80 / 85-series steam vents are for single-pipe steam systems.
Armstrong, Rv-4 One-Pipe Steam Radiator Valve [PDF] available from Armstrong International,
816 Maple Street, Three Rivers, MI 49093 USA, Tel: (269) 273-1415, Armstrong has offices in Beijing, China, Belgium, India and Mexico. Web search 12/27/2010, original source:
http://www.armstronginternational.com/thermostatic-valves-rv-4-one-pipe.
Barnes & Jones Corporation, 91 Pacella Park Drive
Randolph, MA 02368, Tel: 781-963-8000calibrated steam traps and vents, Website: http://www.barnesandjones.com/Email: bnesbitt@barnesandjones.com. Vent-Rite steam vents for radiator control.
Note: Dole air and steam valves are now handled by Eaton - good luck finding the company's contact information, but you can find the products at your local plumbing or heating supplier.
Gorton Heating Corporation, 546 South Avenue East, Cranford, New Jersey 07016, Tel: 908-276-1323, email: info@gorton-valves.com, Website: http://www.gorton-valves.com/ fast venting valves for steam heating systems.
Hoffman 1A ADJUSTABLE STEAM VENTS [PDF] Hoffman Specialty, ITT, web search 12/27/2010, original source:
http://www.drillspot.com/products/51570/Hoffman_1A_Adjustable_Automatic_Air_Vent_For_Steam_Radiators
Hoffman can be contacted at bellgossett.com/hoffman-specialty-products/
Hoffman CONVECTOR STEAM VENTS [PDF] Hoffman Specialty, ITT, web search 12/28/2010, original source:
http://www.hoffmanspecialty.com/pdf/hs900/HS900-conv109.pdf
Hoffman, Special Steam Vents, Hoffman Specialty heating products, web search 12/27/2010, original source:
http://www.hoffmanspecialty.com/pdf/hs900/HS900-3474.pdf
Hoffman Steam and Water Vents, Selection Guidelines - found
in HOFFMAN SPECIALTY CATALOG HS-900G [PDF] - Steam Vents Hoffman Specialty, web search 12/27/2010, original source:
Hoffman can be contacted at bellgossett.com/hoffman-specialty-products/
Holohan, D, "Care & Feeding of Air Vents", Dan Holohan, Old House Journal Online, November 2004
Sid Harvey AIR VENT STEAM VENT CATALOG [PDF] Sid Harvey Industries, Inc
605 Locust Street
Garden City, New York 11530 USA, Tel: (516) 745-9200 Email: sales@sidharvey.com
Brief description of Amtrol Air Purger, Hoffman NO. 40 radiator steam vents and Eaton (Dole) 1-pipe steam system vents. This page includes detailed recommendations among Eaton steam radiator vents for models depending on distance of the radiator from the boiler or from the thermostat. Retrieved 2020/02/28 original source: http://orders.sidharvey.com/IMAGES/catalog/Unpriced/20104-34.pdf
Emerson Swan, Inc.
300 Pond Street
Randolph, MA 02368
Tel: (781) 986-2000
Fax: (781) 986-2028
info@emersonswan.com
Vent-Rite #1 with the Vent-Rite #35 Steam Heat Main air valve. The Vent-Rite #1 (or #11) is designed for 1-pipe steam systems and mounts on the radiator.
The Vent-Rite #35,75, or 77 are intended for main vents (two pipe systems and located on the mains); The Vent-Rite #31 & 33 are used on steam risers and on steam convectors. Contact the company for help or to download their product guide.
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Reader Comments, Questions & Answers About The Article Above
Below you will find questions and answers previously posted on this page at its page bottom reader comment box.
On 2014-10-02 by Adriann - where to buy equivalent/replacement for Dole steam vent valves, sizes 3, 2B and 1A
We are new owners of a 1930's home with 1-pipe steam radiators (been doing my research....) I have Dole valves, sizes 3, 2B and 1A and cannot figure out the equivalent sizes for any other brand.
I have to replace 13 of these 'steam whistles' and would appreciate help in figuring out what size I need, have not had any luck with big box stores as they look at the steam valves with bemusement when I show it to them,
Thanks for any help
On 2014-10-06 by (mod) -
Adriann
You'll be much happier if you give up on the big box stores and stop by a local plumbing and heating supplier, asking for help from their steam expert. At least the larger suppliers usually have someone at hand who knows steam controls and can help you specify the replacement steam vents you need.
Dole made air vents and steam vents: the Dole steam vent was sold in several models, such as the Dole Vari-Vent Air Valve No. 1A, but your sizes 2B and 3 are higher capacity.
Also check our table in the article above where we give Replacement Steam Vent Substitution Sizes for Dole Steam Vents
To remove and replace a steam vent the heat must be off and the radiator cooled to avoid risk of burns. I would NOT remove a vent before locating a local steam vent supplier as I wouldn't want to risk having to leave the house with no heat for a time.
But you don't need to replace with the same brand, just the same type and same threaded tapping size.
On 2014-10-14 by Adriann
Thank you very much for your response, Dan. I will try a plumbing/heater store.
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"Rv-4 One-Pipe Steam Radiator Valve", available from Armstrong International,
816 Maple Street, Three Rivers, MI 49093 USA, Tel: (269) 273-1415, Armstrong has offices in Beijing, China, Belgium, India and Mexico. Web search 12/27/2010, original source:
http://www.armstronginternational.com/thermostatic-valves-rv-4-one-pipe.
"Special Steam Vents", Hoffman Specialty heating products, web search 12/27/2010, original source:
http://www.hoffmanspecialty.com/pdf/hs900/HS900-3474.pdf
"Steam and Water Vents, Selection Guidelines - Steam Vents", Hoffman Specialty, web search 12/27/2010, original source:
http://www.hoffmanspecialty.com/pdf/hs900/HS900-stvents.pdf
Report 95-14, PB96-198163 Thermostatic Radiator Valve (TRV) Demonstration Project, contact NYSERDA. 17 Columbia Circle, Albany, NY 12203-6399 Toll-Free: 1-866-NYSERDA, Tel:(518)465-6252, Ext. 241. Web Search 12/27/2010, original source: http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/96/960509.html
VariValve® Quick-Vent from Heat Timer, adjustable radiator and main line vent valves for one pipe steam systems, web search 12/27/2010, original source: http://www.heat-timer.com/enFiles/ProductDocument/literature/VariV056082C.pdf
"Care & Feeding of Air Vents", Dan Holohan, Old House Journal Online, November 2004
The Steam Book, 1984, Training and Education Department, Fluid Handling Division, ITT [probably out of print, possibly available from several home inspection supply companies] Fuel Oil and Oil Heat Magazine, October 1990, offers an update, (see next item in this list). ITT Fluid Technology,
1133 Westchester Avenue
White Plains, NY 10604,
tel +1 914 304 1700 fax +1 914 696 2950 www.ittfluidbusiness.com
Principles of Steam Heating, $13.25 includes postage. Fuel oil & Oil Heat Magazine, 389 Passaic Ave., Fairfield, NJ 07004.
The Lost Art of Steam Heating, Dan Holohan, 516-579-3046 FAX
Principles of Steam Heating, Dan Holohan, technical editor of Fuel Oil and Oil Heat magazine, 389 Passaic Ave., Fairfield, NJ 07004 ($12.+1.25 postage/handling).
The Heat Efficiency of Steam Boilers, Bryan Donkin
Steam Boiler Operation, Principles & Practice, James J. Jackson
The Steam Book, 1984, Training and Education Department, Fluid Handling Division, ITT [probably out of print, possibly available from several home inspection supply companies] Fuel Oil and Oil Heat Magazine, October 1990, offers an update,
Principles of Steam Heating, $13.25 includes postage. Fuel oil & Oil Heat Magazine, 389 Passaic Ave., Fairfield, NJ 07004.
The Lost Art of Steam Heating, Dan Holohan, 516-579-3046 FAX
Principles of Steam Heating, Dan Holohan, technical editor of Fuel Oil and Oil Heat magazine, 389 Passaic Ave., Fairfield, NJ 07004 ($12.+1.25 postage/handling).
Boilers, Boiler Conversions, James E. Brumbaugh, ISBN 0-672-23389-4 (v. 1) Volume II, Oil, Gas, and Coal Burners, Controls, Ducts, Piping, Valves, James E. Brumbaugh, ISBN 0-672-23390-7 (v. 2) Volume III, Radiant Heating, Water Heaters, Ventilation, Air Conditioning, Heat Pumps, Air Cleaners, James E. Brumbaugh, ISBN 0-672-23383-5 (v. 3) or ISBN 0-672-23380-0 (set) Special Sales Director, Macmillan Publishing Co., 866 Third Ave., New York, NY 10022. Macmillan Publishing Co., NY
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
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