Small square manhole is generally made of 304316l stainless steel plate or carbon steel. The manhole has the advantages of constant pressure discharge, constant pressure suction, flexible opening and closing, safe fire prevention, compact structure, good sealing performance, safety and reliability.

Specification parameters of small square manhole:

Material: 304 (1.4301)

Internal surface treatment: 0.8 μ m-0.4 μ M

External surface treatment: mirror polishing, Matt, sandblasting.

Sealing material: silica gel, EPDM, NBR, fluororubber conforming to fda177.2600;

Access: through manhole, three-way manhole, four-way manhole and inclined manhole.

Explain the working principle of manhole in detail