Every boiler, steam system, or hot water system includes gaskets. They are utilized around the numerous access and inspection handholes and manholes to stop exhaust duct leaks and wherever pipes are connected. If a boiler gasket breaks, the implications are usually serious. Leaks of hot water, steam, or exhaust gases are risky, and decreased efficiency raises operational expenses. Because of this, a boiler gasket should be tested frequently and replaced annually, according to safety experts.
Boilers Basics
Every boiler consists of a heat exchanger and a burner or heating element. Water enters the heat exchanger and is heated to the desired temperature after being chemically treated frequently to prevent corrosion. Temperatures and pressures in a steam-producing boiler can be higher than 380°F and 180PSI.
Steam or hot water enters the piping system through a flue that receives exhaust gases. In steam systems, the vapor cools and condenses, returning the condensate to the boiler for reusing. The exhaust stack of condensing boilers frequently contains corrosive condensate and carbonic acid.
Boiler Maintenance
It is usually preferable to shut down a boiler as part of routine maintenance rather than responding to a leak because doing so is costly and disruptive. The majority of boilers benefit from yearly inspections and cleanings. Efficiency is improved by removing accumulated soot and scale, and components should be tested to ensure proper operation. It’s also a good time to replace gaskets since that requires opening manholes and handholes, even if they don’t appear to be leaking.
Boiler Gasket Components
Fibreglass rope or tape is used for gaskets on the boiler’s fireside. This can handle over a thousand degrees Fahrenheit. Graphite foil, which is frequently shaped into a spiral wound gasket for sealing flanges, is an additional choice.
Tolerance to steam is the main factor on the waterside. Good tensile strength (to withstand internal stresses) and resistance to corrosive acids and water treatment chemicals are secondary criteria. When choosing a boiler gasket, it’s important to remember that many elastomeric gasket materials deteriorate when exposed to heat and oxygen.
Overall, the climate on the waterside favors EPDM gaskets. They have the necessary great steam resistance, high compressibility, and a wide temperature range.
Types of Boiler Gaskets
Soft Gaskets:
- Built using low-temperature components
- High level of compression set
- Not all feed-water chemicals-resistant
- During installation or high-pressure service, extrude
- Vulnerable to shearing if out of alignment
- Overtime creeps
- Not all woven patterns are impenetrable.
- Not fireproof
Hard Gaskets:
- Incredibly challenging to get a seat at first with minimal loading
- Designed to recover relatively little
- Low ability to bend to the radii of the shell
- Possibility of springing when handling
- Due to the design, there is high relaxation but little stability.
- Potential relaxation is enabled by geometry
Tips to Maximize The Life of Gaskets
- Don’t just assume that any rubbery substance will work. Not at all. Purchase boiler seals of high caliber from a reputed vendor.
- Thoroughly clean the areas that will be sealed. Only the metal surfaces, not scale, rust, or fragments of the previous seal, should come into contact with the new seal. However, be careful not to scrape the metal surfaces as this may open a conduit for leaks.
- Do not apply adhesives, sealants, or anti-seize agents on the seal or flanges. As the joint is tightened, these can reduce friction and allow the seal to move.
- In the flange, center the seal. By doing this, the clamping loads are dispersed uniformly over the surface. Failure to do so results in high- and low-load regions that shorten boiler gasket life and encourage leak formation.
- Reduce the seal’s exposed surface area to a minimum. Hot air causes the seal material to oxidize, thus lowering its lifespan. Add shields if further protection from the hot air is required.
- Keep the joint tight enough. This speeds up the material’s ability to take a compression set and will cause early failure.
- Seal life is shortened by excessive heat and pressure. Avoid environments with temperatures and pressures more than 380°F and 180 Bar.
