News and Information

　　 Hygienic manhole What is it?

　　A sanitary manhole is a stainless steel, hygienic‑grade manhole that meets the specific requirements of various media in the food and biopharmaceutical industries. So, do you know what a sanitary manhole is used for?

　　Hygienic manholes are used in stainless steel storage tanks and vessels, where they are required to secure the internal access openings of large tanks and containers. A hygienic inspection well is a negative-pressure inspection chamber, typically fabricated from stainless steels such as 304, 316, 321, or 316L, with a pressure rating of up to 0.3 MPa. Hygienic manholes come in various configurations, including atmospheric‑pressure types, pressure‑rated models equipped with sight glasses, handwheel‑operated versions, as well as rectangular, elliptical, elliptical with integrated mirrors, and square designs.

　　 Hygienic manhole They are typically installed on large storage tanks and vessels in industries such as dairy, brewing, beverage, pharmaceuticals, and bioengineering. Because the application often demands high pressure‑bearing capacity, the strength and sealing performance of hygienic manholes themselves are critical technical requirements. Hygienic manholes are usually mounted at the bottom or top of tanks and are frequently used in conjunction with fire‑extinguishing devices. This not only prevents tank damage and potential casualties in the event of a sudden pressure surge or vacuum emergency caused by an accident, but also provides additional protection for the vessel.

　　When operating sanitary‑grade manholes, it is essential to understand their function. Proper handling and use of inspection manholes are what we all strive for.

　　A sanitary‑grade manhole is an emergency venting device installed on the top of storage tanks. It is typically used in conjunction with fire extinguishers and mechanical vent valves. Not only does it prevent accidents caused by sudden overpressure or vacuum in the tank, but it also helps protect the tank from damage. This device serves to safeguard the tank and is especially suitable for atmospheric‑pressure dome‑top tanks equipped with nitrogen sealing at the top. So, do you know how to calculate the installation cost of a sanitary‑grade manhole?

　　The direct costs of installing a sanitary‑grade manhole are as follows:

　　1. The price of the primary materials refers to the purchase cost, including freight, handling fees, and other related expenses.

　　2. Machinery: Refers to the utilization of machine shifts, as well as the depreciation costs of machinery, such as the maintenance expenses for production equipment like stamping and polishing machines.

　　3. Auxiliary materials include: expenses incurred during the manufacturing process, such as utility costs (water and electricity), welding electrodes, polishing discs, other consumable materials, and machinery maintenance fees.

　　4. Labor costs refer to the wages and related expenses of construction workers.

　　Indirect expenses refer to the company’s telephone charges, telecommunications network fees, business entertainment and travel expenses, office expenses, insurance premiums, as well as salaries and benefits for managerial personnel. The steel plates selected for stainless steel manholes have a thickness of 0.8 mm to 1.0 mm. Following the storage of large volumes of liquid, concerns have been raised regarding whether the structural strength requirements can still be met. Relevant technical and design data indicate that the material thickness is relatively thin.

　　The direct costs of installing sanitary‑grade manholes primarily consist of the aforementioned expenses. It is now essential for all of us to understand the installation costs associated with sanitary‑grade manholes. Proper operation of inspection chambers is what we all strive for.