The installation of safety valves and the key points of pipeline layout design

1. The safety valve should be installed upright and close to the protected equipment or pipeline. If the arrangement cannot be approached, the total pressure drop of the pipeline from the protected equipment or pipeline to the inlet of the safety valve should not exceed 3% of the fixed pressure value of the safety valve.

2. A maintenance platform should be set up for safety valves. When arranging heavy safety valves, the possibility of lifting them after disassembly should be considered, and if necessary, suspension rods should be installed.

3. The inlet pipeline of the safety valve should use a long radius elbow.

4. The design of the outlet pipeline of the safety valve should consider that the back pressure does not exceed a certain value of the safety valve's constant pressure. For ordinary spring type safety valves, the back pressure shall not exceed 10% of the fixed pressure value of the safety valve.

5. When the medium discharged into the vent main or to the flare main contains condensate or condensable gas, the outlet of the safety valve should be higher than the main pipe; Otherwise, drainage measures should be taken.

6. The outlet pipeline of the safety valve discharged into the closed system should be inclined at a 45 ° angle along the medium flow direction at the top of the discharge main pipe to prevent the condensate in the main pipe from flowing back into the branch pipe, and to reduce the back pressure of the safety valve.

7. When a shut-off valve is installed on the inlet and outlet pipelines of the safety valve, a single gate gate valve should be selected and sealed with lead. The valve stem should be installed horizontally to prevent the valve plate from sliding down when the pins connecting the valve stem and valve plate are corroded or loose. When a safety valve is equipped with a bypass valve, the valve should be sealed with lead.

Concept classification of one-way valves and practical application of products

One way valve, also known as check valve or check valve. Used in hydraulic systems to prevent reverse oil flow.

There are two types of one-way valves: straight through and right angle. The straight through one-way valve is installed on the pipeline with a threaded connection. There are three types of right angle one-way valves: threaded connection, plate connection, and flange connection. Hydraulic control one-way valve, also known as locking valve or pressure maintaining valve, is the same as one-way valve to prevent reverse flow of oil. But when reverse oil flow is required in the hydraulic circuit, the control oil pressure can be used to open the one-way valve, allowing the oil flow to flow in both directions. The hydraulic control one-way valve adopts a conical valve core, so the sealing performance is good. When it is required to close the oil circuit, this valve can be used as a one-way lock of the oil circuit to maintain pressure. There are two ways for hydraulic control one-way valves to control oil leakage: internal leakage and external leakage. Internal leakage type can be used in oil circuits with no backpressure at the reverse outlet of oil flow; Otherwise, an external leakage type is required to reduce the control oil pressure.