Spitting or Hissing Air Vents

  1. The system is dirty. Steam heating systems are constantly corroding. …
  2. Other vents are not working as they should. …
  3. There are no main vents on the system. …
  4. The vents are the wrong size for their location. …
  5. The boiler is oversized or overfired. …
  6. The system has motorized zone valves.

Why is my steam radiator hissing?

A constant hissing sound throughout the heating cycle usually means the air vent is not closing at the right time and is failing to trap the steam inside the radiator. An air vent that’s spitting or leaking water may be partially obstructed with mineral deposits or other debris.

Why do steam pipes make noise?





Knocking radiator sounds are generally a sign of trapped water or air in the system. When either gets stuck, steam is prevented from moving through the pipe into the radiator. This pressure build up can make a loud knocking or banging noise.

How does a steam air vent work?

During a heating cycle, steam flows up through the supply pipe to the radiator (assuming the main radiator valve is open). As the radiator fills with steam it pushes the air out through the open vent. This release of air pulls steam into the vent.

Can a steam heater explode?

Aging Steam Systems



Unseen, pipe-thinning corrosion inside pipes and the boiler can result in a burst pipe or boiling chamber, causing an explosion or a sudden blast of steaming hot vapor.

Can steam pipes cause fire?

Among the most important causes of fires in manufacturing establishments, says the ” Bulletin of the National Association of Wool Manufacturers,” for July, is danger from steam pipes; the danger being greater because the steam or hot-water pipes being introduced as a measure of precaution against fires, liability from

Can steam radiators start fires?





Steam can cause more severe burns than water because it may be superheated, but the severity of steam burns are usually lower than those caused by fire, Dr. Gallagher said.

Should steam pipes be insulated?

Any surface over 120°F should be insulated, including boiler surfaces, steam and condensate return piping, and fittings. Insulation frequently becomes damaged or is removed and never replaced during steam system repair.

How hot can a steam pipe get?

Relationship of Boiler Pressure to Water Temperature in Steam Boilers. The temperature of heated water can exceed 212 °F when water is heated under pressure – producing superheated water than can flash to steam.

What kind of pipe is used for steam?

carbon steel



Pipes for steam systems are commonly manufactured from carbon steel to ASME B 16.9 A106. The same material may be used for condensate lines, although copper tubing is preferred in some industries.

Can PEX be used for steam heat?

No. PEX is plastic and is not rated for steam, which reaches temperatures of 212ºF.

Can copper pipe be used for steam heat?

Everyone knows that copper tube has a proven history in use in a variety of applications, however a common question is “can I use copper tube in a steam system?” Just like in water systems, copper tube has long been used in both steam and steam condensate piping systems.

What happens when a steam trap fails?



When a steam trap fails open, it simply acts like an open valve and hence, a lot of steam would leak through it. As a result, the overall steam consumption of the plant will go up, reducing the efficiency of the operation.

How do you know if you have a bad steam trap?

Condensate should usually be flowing through a trap, and the sound should have a lower pitch. So, if this sound changes and appears much closer to a higher pitched sound like that of steam flow, then the trap may have a large amount of flash steam or may be leaking live steam and should be inspected further.

How do I know if my steam trap is failing?

When a steam trap fails open, steam will blow through the trap and energy is wasted. With the valve open, hot steam discharges continually. More than likely dirt has accumulated on the valve seat or the trap bellows has failed.