1) Manhole Cover is equipped on the top of tank truck.

2)  It is the entrance of fluid transfer operation inspection and maintaining the inside tank. It can protect the tank when involving in an emergency.

3) Under normal practice, vent is closed When loading and unloading and temperature variation,  it will cause the pressure variation inside the tank, such as air pressure and negative vacuum pressure, the vent of manhole cover will be closed automatically in order to keep the tank under a normal pressure.

4)  When involving in emergency, such as a car accident, the Emergency Exhaust Valve will open the inside tank, meets the setting, in order to prevent explosion.

5) It is internationally accepted, and specified, by oil companies  around the world to assist with the safe transportation of petroleum based products.    

6) Features Benefits:

a. Material: Coated stell

b. Pressure and vacuum vent fitted as standard for tank breathing. Various ratings are available to meet operational requirements.

c. Automatic sealing of the P/V vent in a roll over situation prevents dangerous and costly spillage.

d. Steel cover arm exceeds the requirements of the Australian DROP tests(AS 2809-2-1990)

e. Two-stage opening allows safe release of residual compartment pressure before fully opening the fill cap.

f. 250mm(10)fill hole for easy drop pipe insertion when top loading.

g. High quality baseplate and component materials, to international standards, are used for durability and performance.

7) Technique Specification

a. Setting pressure of vent discharge : 7.14Kpa

b. Negative opening pressure:-2Kpa~-3Kpa

c. Setting pressure of emergency exhaust valve: 0.0266Mpa±0.001Mpa

d. Pressure resistance:0.254Mpa

8) Materials:

   Cover: Steel

   Weld Ring: Steel

   Gasket: Buna-N