The majority of our butterfly valve product testing factory inspection and type test is divided into two categories. Butterfly valve type of inspection refers to conduct a comprehensive assessment of product quality butterfly valve, namely technical requirements specified in the standard are fully test (if necessary, but also increase test items), called type test, also known as routine tests.
1)When one of the following circumstances, butterfly valve type inspection should be carried out in general:
(1)New products or old products to the plant trial to identify stereotypes for the butterfly valve;
(2)The official production, such as structure, materials, technology has drastically changed, which may affect the valve performance;
(3) Normal production, after regular or accumulate a certain output, a test should be carried out periodically;
(4) Butterfly valve long shutdown, resume production;
(5) The factory test results and the last type testing when there is a big difference;
(6) The State Administration of Quality Supervision bodies type inspection requirements.
1)When one of the following circumstances, butterfly valve type inspection should be carried out in general:
(1)New products or old products to the plant trial to identify stereotypes for the butterfly valve;
(2)The official production, such as structure, materials, technology has drastically changed, which may affect the valve performance;
(3) Normal production, after regular or accumulate a certain output, a test should be carried out periodically;
(4) Butterfly valve long shutdown, resume production;
(5) The factory test results and the last type testing when there is a big difference;
(6) The State Administration of Quality Supervision bodies type inspection requirements.
Check butterfly valve type test taken from the factory quality inspection departments qualified stock butterfly valve randomly selected method, or from a user-supplied but used a random sample method butterfly. The number of units and the minimum number of sampling units for each specification sampling valve according to regulations. When the user sampling, sampling for several unlimited number of sampling units based upon the requirements. When the entire family quality assessment, sampling department can be extracted from the series according to the situation two to three typical specifications butterfly test specifications for each sample based upon a predetermined minimum number of units and the number of sampling units.
2)Technical requirements and test methods for butterfly valve type test according to regulations. Each test subject butterfly valve housing, sealing test, leak tightness tests must meet all the technical requirements specified. The remaining types of test items, if they are seized with a butterfly valve in an index less than the prescribed technical requirements, it is allowed for the sample from the sampling valve in taking further the number of units required. When tested again, all the test items must comply with the technical requirements, or as unqualified goods.
Butterfly valves have the worm gearbox flange end hard seated single eccentric butterfly valve and worm gearbox flange end hard seated triple eccentric butterfly valve.
The worm gearbox flange end hard seated single eccentric butterfly valve represents the center of the butterfly valve,which is the valve stem axis, the center of the disc and the center of the body in the same position. Its advantages are simple structure, easy manufacturing, the disadvantage is due to the butterfly valve plate and seat is always in the squeeze, scratch state resistance from large, fast wear. Seat basically elastic material such as rubber and Teflon, so the temperature is limited only for low temperatures. The worm gearbox flange end hard seated single eccentric butterfly valve 150LB ~ 600LB ventilation valve in the metallurgical, chemical, building materials, power plants, glass and other industries in ventilation, dust cold or hot gas pipeline environmental projects, as the gaseous medium to regulate the flow or cutting device.
The triple offset butterfly valve, the valve stem axis refers to both departing from the center of the disc deviate from the center of the body, the shape of the cone Sealing is not a positive, but taper. The advantage is high temperature, good sealing performance. Triple eccentric butterfly valve 150LB ~300LB metal seal butterfly valve using sophisticated J-shaped elastic ring and three eccentric multi-level metal seal structure,which is widely used in medium temperature ≤425 ℃ of metallurgy, electric power, petrochemical, and water supply and drainage and municipal on construction and other industrial pipeline, for regulating the flow and the carrier off fluid use.
Should you want to know more about butterfly valve from Reliable China valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.
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