Marine PV valve (pressure/vacuum valve for cargo oil tank) is also called as high-velocity relief valve, high velocity P/V valve, generally used in the relief system of the oil tanker and chemical tanker, according to the current regulations IMO and IBC. The purpose of the high velocity valve is to provide automatic control of pressure differentials during liquid cargo ship loading, voyage, ballasting and de-ballasting without any manual operation, also, it provides auto-protection against fire and explosions on deck. Additionally in the event that the inert gas system can not supply gas promptly, the vacuum valve can auto open to protect the tank against excessive vacuum when de-ballasting on dock. Normal, when the pressure risen in tank because of temperature or loading, the pressure valve open automatically and vent gas. When the pressure of tank come to pressure differentials, the vacuum valve or pressure valve all can be automatic resetted. If an ignition occurs outside the tank space, the flames will be quenched in the flame trap.
A gas freeing cover is necessary while doing other works in the tank such as cleaning, removing the gas. Because such works needs ventilation and the pressure can not work when the pressure is not low or without pressure.
The pressure valve can not be opened manually, and it works with the velocity do not smaller than 30m/s.
High velocity PV relief valve’ Specification:
- Material: Cast Steel or Stainless Steel
- Flange Standard: GB, JIS, DIN, ANSI, BS
- Opening Pressure of Vacuum Valve: -3.5kPa
- Opening Pressure of Pressure Valve on the oil tank is 14kPa, on the chemical tank is 20kPa.
- The opening pressure of the pressure may be different, but the differences of opening pressure and flow range is inapparent if the pressure valves have the same diameter.
Marine Size List (mm):
* The flange size in the list as per GB2501.We also can machine the flange as per JIS, DIN, ANSI.