The principle of the safety valve is that when the load exceeds the set pressure of the safety valve, the safety valve will open, thus preventing the roots blower from failure. Generally, the threshold value of the safety valve is when the set pressure exceeds 10% of the pressure rise.
Precautions for use of safety valve of Roots blower:
Because the safety valve of the fan should work under low pressure, the contact surface between the valve seat and the valve body is precision machined. If there is foreign matter attached around the valve seat, the foreign matter will be adsorbed on the contact surface when the valve body is working, thus causing leakage. In addition, please check whether the safety valve is impacted during handling, which is also the cause of leakage.
Setting method of safety valve of Roots blower
Principle: When the load exceeds the set pressure of the safety valve, the safety valve will open, thus preventing the roots blower from failure.
Setting method:
Move the Roots blower, observe the pressure gauge while tightening the gate valve to make the pressure exceed the set pressure by about 10%. Loosen the locking nut and rotate the adjusting screw counterclockwise until air is discharged from the safety valve.
If the set pressure has not been reached during the process of tightening the gate valve, and the safety valve has discharged air, please rotate the adjusting screw clockwise again until the air is no longer discharged, and then rotate counterclockwise until the air is just discharged again (clockwise rotation, the set pressure becomes higher; counterclockwise rotation, the set pressure becomes lower).
Tighten the lock nut and adjusting screw. Loosen the gate valve and reduce the pressure so that the safety valve will not exhaust.
Check whether the safety valve works under the set pressure, and tighten the gate valve again to increase the pressure. Note: when there is load on the exhaust side, if the gate valve is fully opened, the set pressure is about 10% higher than the actual load.
Setting method of safety valve: ① Start Roots blower. ② While observing the pressure gauge, tighten the gate valve to make the pressure exceed the set pressure by about 10%. ③ Loosen the locking nut and rotate the adjusting screw counterclockwise until air is discharged from the safety valve. ④ If the set pressure has not been reached and the air has been discharged from the safety valve during the process of tightening the gate valve, please rotate the adjusting screw clockwise again until the air is no longer discharged, and then rotate counterclockwise until the air is discharged again. ⑤ Tighten the lock nut and adjusting screw. ⑥ Loosen the gate valve and reduce the pressure so that the safety valve will not exhaust. ⑦ Check whether the safety valve works under the set pressure, and tighten the gate valve again to increase the pressure.
The safety valve of Roots blower is used to protect the safety of the blower and equipment. When the pressure in Roots blower and equipment abnormally rises to a specified value (the opening pressure of the safety valve), the safety valve can automatically open and discharge the medium to prevent the pressure from rising further; When the pressure in roots blower and equipment drops to a specified value (reseating pressure of safety valve), the safety valve will automatically close.
(1) The safety valve shall be installed vertically and close to the protected equipment or pipeline. If it cannot be arranged near, the total pressure drop of the pipeline from the protected equipment or pipeline to the inlet of the safety valve shall not exceed 3% of the constant pressure value of the safety valve.
(2) The safety valve should be equipped with a maintenance platform. When arranging the safety valve with large weight, the possibility of lifting after the safety valve is disassembled shall be considered, and the suspender shall be set if necessary.
(3) Long radius elbow shall be adopted for inlet pipe of safety valve.
(4) The design of the outlet pipeline of the safety valve shall consider that the back pressure shall not exceed a certain value of the constant pressure of the safety valve. For ordinary spring type safety valve, its back pressure shall not exceed 10% of the constant pressure value of the safety valve.
(5) When the medium discharged into the vent header or flare header contains condensate or condensable gas, the outlet of the safety valve shall be higher than the header; Otherwise, drainage measures shall be taken.
(6) The outlet pipeline of the safety valve discharged into the closed system shall be mitered at the top of the discharge header at 45 ° along the flow direction of the medium, so as to prevent the condensate in the header from flowing back into the branch pipe and reduce the back pressure of the safety valve,
(7) When a shut-off valve is set on the inlet and outlet pipeline of the safety valve, a single gate valve shall be selected and lead sealed. The valve rod shall be installed horizontally to prevent the valve plate from sliding down when the pin connecting the valve rod and the valve plate is corroded or loosened. When the safety valve is equipped with a bypass valve, the valve shall be lead sealed off.
I believe that after reading the above contents, you should also understand the reason for setting the safety valve at the outlet of Roots blower. I hope it will help you.
Text label: Roots blower
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