Issues regarding the adjustment and calibration of safety valves
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This post was last edited by FORREST_GUMP on 2015-11-6 at 20:21. Now we need to create a container, and there are several questions regarding safety valves – please help us out. 1. After purchasing the safety valves, do they need to be sent to a testing institute for inspection, or is a quality certificate from the manufacturer sufficient? 2. Since the opening pressure of the safety valve is 1.35 MPa while the pressure test requires 2.5 MPa, the safety valve should first be adjusted to 2.85 MPa; after the pressure test is completed, it can then be adjusted back to 1.35 MPa. Should we adjust the safety valve ourselves, or should it be done by the person in charge of supervision and inspection?
It can only be used after being inspected. A safety valve is not necessary during the airtightness test. Install the safety valve again after testing.
Our factory has its own valve team, which is responsible for pressure testing valves, setting the pressure for safety valves, and carrying out simple repairs on valves; to do this, it is necessary to have the appropriate qualifications. The device is pressure-tested and airtight; if required, it may be supplied without a safety valve.
1. After purchasing the safety valve, it needs to be sent to a testing institute for calibration. Manufacturers generally do not provide calibration certificates, unless it is requested at the time of purchase. 2. It is not specified that a safety valve must be installed during the pressure test. A pressure test of 2.5 MPa and a safety valve setting of 1.35 MPa are acceptable. If it is a gas-tightness test, a safety valve must be installed. If the airtightness test pressure is 2.5 MPa, the setting pressure of your safety valve must be higher than 2.5. Pneumatic testing and airtightness testing are not the same thing! 3. Additionally, after calibration, the safety valve is equipped with a lead seal. It cannot be adjusted casually.
I took a look; it’s a gas-tightness test. If there’s a seal in place, it can’t be adjusted casually. Then who should be responsible for carrying out the pressure adjustment?
The set pressure of your safety valve is incorrect; it should be greater than 2.5 MPa. You need to take it to a safety valve calibration facility for adjustment.
It is necessary to have it inspected and certified by the local quality supervision bureau (for safety valve testing). If adjustments are needed, as long as the range permits, it can be asked of the testing center to make them. :):):)
Your safety valve has a specified range of adjustment; it can’t be adjusted however one wants. For calibration, one must go to a specialized inspection agency
This post was last edited by zhangjuhua on 2015-11-7 at 14:59. 4.8.3 Airtightness test: (1) The gas used for the airtightness test shall comply with the requirements specified in item (1) of section 4.7.7.1 of these regulations; the test pressure shall be the design pressure of the pressure vessel； (2) When conducting a airtightness test, the safety accessories should generally be fully installed ； (3) It is considered qualified if no leakage is detected after maintaining the pressure for a sufficient time. It’s lazy to use a sealed design without a safety valve, haha
The set pressure of this safety valve is lower than the airtightness test pressure, which is not acceptable. The purpose of a safety valve is to protect the equipment, and its operating pressure should be high enough. You can’t reset the safety valve every time you perform a leak test!
The normal operating pressure is only 1.1 MPa, but the customer insists that it be designed for 2.5 MPa; therefore, the airtightness rating is 2.5 MPa, while the normal operating pressure remains at 1.35 MPa. The airtightness test can be done just once; it shouldn’t be troublesome