Shanghai Henghe Petrochemical Equipment Co., Ltd
Home>Products>Emergency emptying manhole (HXF-R)
Firm Information
  • Transaction Level
    VIP member
  • Contact
  • Phone
    13917469809
  • Address
    No. 3 Lingguang Building, Lane 108, Hengfeng North Road, Shanghai
Contact Now
Emergency emptying manhole (HXF-R)
According to the national standard "Fire Protection Design Code for Petrochemical Enterprises" (GB50160-90), the fixed top tank for Class A and Class
Product details

Product Features

According to the national standard "Fire Protection Design Code for Petrochemical Enterprises" (GB50160-90), "Fixed top tanks for Class A and Class B liquids shall be equipped with flame arresters and breathing valves". It can be seen that breathing valves and flame arresters are indispensable safety facilities for storage tanks. It can not only maintain the pressure balance of the storage tank, ensuring that the tank is damaged in case of overpressure or vacuum, but also reduce the volatilization and loss of the medium inside the tank. This valve is installed on the top of the nitrogen sealed tank and is a safe and energy-saving product that maintains the pressure balance of the storage tank and reduces the volatilization of the medium. It is often used in conjunction with flame arresters.

The emergency vent manhole is a rapid pressure relief device with the same technical performance and main component materials as the breathing manhole.


product mix


Main technical parameters:
Shell material: carbon steel, aluminum alloy, stainless steel (SUS304, SUS304L, SUS316, SUS316L), fluorine lining, plastic
Internal core components: valve disc, valve seat, valve stem, valve sleeve. Internal core material: stainless steel or polytetrafluoroethylene.
Sealing ring material: polytetrafluoroethylene.
Environmental temperature: -40~+60OC.
Operating pressure:
Type A:+355Pa (+36mmHg), -295Pa (-30mmH20)
Type B:+980Pa (+100mmH20), -295Pa (-30mmH20)
Type C:+1750Pa (+180mmHg), -295Pa (-30mmH20)
D-type: Special pressure, specified by the user.
Fireproof layer material: stainless steel.
Explosion proof level: BS 5501: IIA, IIB, IIC.
Flange standards: GB, HG, SH, HGJ, JB, ANSL, JIS and other standards. (User specified, please indicate pressure level)
Manufacturing and testing standards: Manufacturing and acceptance shall be carried out in accordance with standards such as SY7511-87 for oil tank breathing valves and GB5908-86 for fire resistance performance and test methods for oil tank flame arresters; Or user specified standards.
Main external dimensions:

Nominal diameter DN External dimensions
H φ
450 370 658
500 380 708
600 480 808
700 540 908
750 600 955






Installation And Maintenance

1. After arrival at the construction site, if installation is temporarily not carried out or if the factory undergoes major repairs or maintenance in the future, it should be stored in a warehouse with rainproof facilities. Breathing valve series products must not be inverted during transportation.
2. Common faults of breathing valves include air leakage, jamming, adhesion, blockage, freezing, rusting, and constant opening of positive pressure valves and vacuum valves. Some of these faults can cause the breathing valve to fail to operate when it reaches the control pressure, resulting in overpressure in the oil tank and endangering its safety; Some can cause the breathing valve to lose its function, leading to uncontrolled large and small breathing, which in turn increases the evaporation loss of fuel, lowers the quality of fuel, or exacerbates air pollution around the tank, increasing regional risk factors.
3. In addition to daily inspection and maintenance, the breathing valve should also undergo comprehensive inspection and maintenance on a regular basis. Generally, it should be inspected twice a month in the first and fourth quarters of each year, and once a month in the second and third quarters. The main contents of inspection and maintenance include:
① Open the top cover of the breathing valve, check for rust and scale on the valve disc, valve seat, guide rod, guide hole, spring, etc. inside the breathing valve, and clean them with kerosene if necessary;
② Check whether the valve disc opens and closes flexibly, whether there is any jamming phenomenon, and whether the contact surface (sealing surface) between the valve disc and the valve seat is good. If necessary, it should be removed and repaired. The material of the sealing surface is non-ferrous metal, and lubricating oil abrasive should be used for grinding;
③ Check whether the valve body seal is intact, whether there is freezing or blockage, and wipe off the dirt and dust on the net to ensure smooth gas flow;
④ Check if the gland gasket is tight and replace it if necessary;
⑤ Add oil to the bolts for protection.
⑥ The paint on the inner and outer surfaces of the breathing valve product casing should be repainted annually.

Ordering Instructions

When placing an order, the following parameters must be determined: ① caliber; ② Work pressure; ③ Material; ④ Flange standard; ⑤ Medium; ⑥ Operating pressure; In order to provide you with suitable products.



Online inquiry
  • Contacts
  • Company
  • Telephone
  • Email
  • WeChat
  • Verification Code
  • Message Content

Successful operation!

Successful operation!

Successful operation!