High-velocity relief valve (pressure vacuum valve) is the controlled venting system which is necessary for oil tanker and chemical tanker. The series of DF-type P/V valve is a new generation production without vibration and anti-collision...The pressure/vacuum valve is installed on the vent pipe of oil tanker and chemicals tanker. It is the only entry and exit for liquid cargo tank.
Main Parts of the DF-ISO high velocity relief valve
| Serial No. | Parts | Quantity | Material |
| 1 | P-valve base | 1 | 20# |
| 2 | P-valve seat | 1 | 316 |
| 3 | P-valve body (a) | 1 | 20# |
| 4 | P-valve body (b) | 1 | 20# |
| 5 | Director (P-valve disc ) | 1 | 316 |
| 6 | Clump weight | 1 | 316 |
| 7 | P-valve spindle | 1 | 316 |
| 8 | Lifting shaft | 1 | 316 |
| 9 | Climbing cam | 1 | 316 |
| 10 | Positioning board | 1 | 316 |
| 11 | Lifting handle | 1 | 316 |
| 12 | Bush | 1 | 304 |
| 13 | Nameplate | 1 | 304 |
| 14 | Lifting pin | 1 | 316 |
| 15 | V-valve body | 1 | 20# |
| 16 | V-valve disc | 1 | 316 |
| 17 | V-valve seat | 1 | 316 |
| 18 | Small spacer ring of flame screen | 1 | 316 |
| 19 | Flame screen | 2 | 316L |
| 20 | Big spacer ring of flame screen | 1 | 20# |
| 21 | Flame screen gland | 1 | 20# |
| 22 | V-valve cover | 1 | 20# |
Main performance parameter
| Model | Opening pressure (kPa) |
Rated working pressure (kPa) |
Flow rate (m3/h) |
Outlet air flow velocity of pressure valve(m/s) | |||||
| Pressure valve | Vacuum valve | Pressure valve | Vacuum valve | Air removal cover | Pressure valve | Vacuum valve | Air removal cover | ||
| DF250 | 14.0-21.0 | -3.5~-7.0 | 21.0 | -7.0 | 2.0 | ＞3500 | ＞3500 | ＞1200 | ＞30 |
1.The high-velocity relief valves with different specification have the same diameter and performance parameter;
2.The opening pressure of the vacuum valves are -3.5kpa; the opening pressure of the pressure valves 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 if the pressure valves have the same diameter.
