Hydraulic shut-off valve
Abbreviation: hydraulic cut-off valve, oil pressure cut-off valve, emergency cut-off valve hydraulic emergency cut-off valve
Model: QDY421F-25/40C QDY421F-25/40P
Introduction to shut-off valve:
The shut-off valve is a normally closed structure, which is normally closed, and the valves that are opened for a short time during loading and unloading operations:
The hydraulic cut-off valve is installed in front of the manual liquid ammonia cut-off valve in the downstream pipeline of the storage tank, which can be both the discharge port and the feed port (installation method: pressure bearing direction/storage tank position→ discharge port/feed port). The manual oil pump is installed 15-20 meters away from the valve. The pressure of the manual oil pump is transmitted to the hydraulic cut-off valve actuator through the on-site staff, and the valve is opened, During the loading and unloading process, the security inspector shall not leave the position of the manual oil pump (the hydraulic cut-off valve is operated by the pressure of the oil pump, and the security inspector shall stick to the position. In case of leakage, tank car sliding or other emergencies, the pressure of the oil pump can be removed at the first time, and the hydraulic cut-off valve can be quickly closed). After the loading and unloading is completed, the security inspector shall unscrew the pressure retaining valve (needle valve) of the oil pump The oil pressure returns to the oil chamber of the oil pump tank along the connecting pipe, and the cut-off valve is closed. The security inspector checks that all equipment is normal, then instructs the tanker to unload the hose, and the tanker starts to leave.
Technical parameters of hydraulic emergency shut-off valve:
| Nominal pressure MPa | two point five | four |
| Shell test pressure MPa | three point seven five | six |
| Sealing test pressure MPa | two point seven five | four point four |
| Applicable temperature | -40℃~+150℃ |
| Applicable media | Ammonia, liquid ammonia, liquefied gas, refrigerant, etc |
| Flange standard | GB/T9113-2000 |
| Manufacturing standard | JB/T9092-1999 |
| Emergency cut-off time | ≤ 5~10 seconds |
| Melting temperature of fusible plug | 75± 5℃ |
| Applicable medium of oil cylinder | Synthetic spindle oil, transformer oil |
| Cylinder pressure MPa | 4.0~6.0 |
Possible faults and solutions
Oil cylinder leaks
Causes: 1. The seal O-ring is damaged, 2. The oil cylinder, piston and guide sleeve are rusted.
Elimination method: 1. Replace O-ring; 2. Remove rust and oil
Leakage of sealing surface
Causes: 1. The sealing surface is damaged; 2. The spring is broken or invalid; 3. The adjusting nut is too tight; 4. The valve flow direction is wrong.
Elimination method: 1. Replace the seal ring to remove dirt; 2. Replace the spring; 3. Adjust the nut; 4. Install according to the valve body mark
Leakage of intermediate flange
Causes: 1. The connecting bolts are uneven or not tightened; 2. The sealing gasket is damaged.
Elimination method: 1. Tighten the nuts evenly; 2. Replace the O-ring.
External dimension and connection dimension of emergency shut-off valve: Unit: mm
Nominal diameter
DN | PN4.0MPa |
| L/valve length | D/Flange outer diameter | D1/center hole distance | D2/Flange contact surface | D6/concave dimension | B/Flange thickness | Z -∅ d/bolt hole | H/center distance | Do/outer diameter of hand wheel |
| fifteen | one hundred and thirty | ninety-five | sixty-five | forty-five | forty | sixteen | 4-∅ fourteen | two hundred and thirty-three | one hundred and twenty |
| twenty | one hundred and fifty | one hundred and five | seventy-five | fifty-five | fifty-one | sixteen | 4-∅ fourteen | two hundred and seventy-five | one hundred and forty |
| twenty-five | one hundred and sixty | one hundred and fifteen | eighty-five | sixty-five | fifty-eight | sixteen | 4-∅ fourteen | two hundred and eighty-five | one hundred and sixty |
| thirty-two | one hundred and eighty | one hundred and thirty-five | one hundred | seventy-eight | sixty-six | eighteen | 4-∅ eighteen | three hundred and two | one hundred and eighty |
| forty | two hundred | one hundred and forty-five | one hundred and ten | eighty-five | seventy-six | eighteen | 4-∅ eighteen | three hundred and fifty-five | two hundred |
| fifty | two hundred and thirty | one hundred and sixty | one hundred and twenty-five | one hundred | eighty-eight | twenty | 4-∅ eighteen | three hundred and seventy-three | two hundred and forty |
| sixty-five | two hundred and ninety | one hundred and eighty | one hundred and forty-five | one hundred and twenty | one hundred and ten | twenty-two | 8-∅ eighteen | four hundred and eight | two hundred and eighty |
| eighty | three hundred and ten | one hundred and ninety-five | one hundred and sixty | one hundred and thirty-five | one hundred and twenty-one | twenty-two | 8-∅ eighteen | four hundred and thirty-six | three hundred and twenty |
| one hundred | three hundred and fifty | two hundred and thirty | one hundred and ninety | one hundred and sixty | one hundred and fifty | twenty-four | 8-∅ twenty-three | four hundred and eighty | three hundred and sixty |
| one hundred and twenty-five | four hundred | two hundred and seventy | two hundred and twenty | one hundred and eighty-eight | one hundred and seventy-six | twenty-eight | 8-∅ twenty-five | five hundred and fifty-eight | four hundred |
| one hundred and fifty | four hundred and eighty | three hundred | two hundred and fifty | two hundred and eighteen | two hundred and four | thirty | 8-∅ twenty-five | six hundred and eleven | four hundred |
Related products include: Ammonia stop valve Electric shut-off valve Emergency shut-off valve
