Manhole Gaskets

Most boilers have access ports built into them. These are sealed by oval shaped lids. Gaskets suitable for use with manholes come in three broad styles.

A. Rubber
A specially formulated rubber is used to withstand the constant temperature and pressure to which these gaskets are subjected. A rubber gasket should not be used above 180 deg. C.

B. Fiber Glass
Vulcanized fiberglass may be used instead of rubber and above 180 deg. C. This type of gasket consists of soft woven fiberglass bonded with rubber to give it resilience so that it will seal.

C. Spiral wound
A specially shaped spiral wound may be used. In this case the spiral is wound in an oval and does not have inner or outer rings. Used where temperatures limit the use of rubber and fiberglass. The oval access doors must have well finished seating surfaces for this style of gasket to work properly.