For a new project, is it necessary to conduct pressure tests on all valves before installation?

For new projects, all valves must undergo pressure testing before installation. Should air pressure or water pressure be used for this testing? Depending on the actual conditions of one’s company, the common practice is to apply water pressure. As for control valves, if a company does not have the necessary facilities, it is not necessary to carry out pressure testing; this is because control valves come with pressure testing reports upon leaving the factory, and they are also subjected to separate calibration tests by the construction team on site, with corresponding calibration records available

For new projects, all valves must undergo pressure testing before installation; those that fail the test must be replaced, otherwise many problems will arise after the system is put into operation. Due to funding issues in the early stages and pressure to meet deadlines at our facility, many valves started leaking after they were put into use, which caused various pieces of equipment to stop working and forced us to suspend operations for maintenance. In some cases, the valve discs even came off, disrupting normal production. Therefore, it is very important to choose a manufacturer with high quality standards and to conduct pressure testing before installation. Otherwise, one will have to pay for their actions sooner or later.

In accordance with the \"Code for Construction and Acceptance of Industrial Metal Piping Projects\" GB50235—97, valve inspection: (1) Review of quality certification documents. Upon receipt of valves and fittings, it is necessary to check the quality certification documents, which should include the name of the manufacturer as well as its safety registration information. Product production date ； Product name, specifications, and model ； Nominal pressure, nominal diameter, applicable medium, and applicable temperature ； Based on standards, inspection results, and inspection date ； Factory serial number ； Signature of the inspector and responsible personnel. Check the nameplate on the valve body; it should indicate the manufacturer’s name, valve model, nominal pressure, nominal diameter, and the direction of flow of the medium. (II) Visual inspection of the valve: 1. The valve must not have any damage, missing parts, corrosion, or detached nameplates; there must be no dirt inside the valve body. The valves should be equipped with protective covers at both ends, and the handles or handwheels must operate smoothly and effortlessly, without any sticking. 2. The surface of the cast valve body should be smooth and even, free from defects such as cracks, shrinkage cavities, sand holes, pores, and burrs. The valve disc or plug of the check valve must operate smoothly and accurately, without any eccentricity, displacement, or skewing. 3. The sealing surface of the valve flange should be flat and smooth, without any radial scratches. (III) Inspection and testing of valves 1. Inspection and testing before valve installation (1) Before installation, the valve body and sealing surfaces of the valve, as well as the materials of gaskets and packing with special requirements, should be sampled and inspected in accordance with the provisions of the design documents. (2) For alloy steel valves, the material of the internal components shall be sampled and tested using spectral analysis or other methods; at least 1 sample per batch is required. When applying the SH3501—2002 standard, the valve bodies of alloy steel valves shall be subjected to spectral analysis on a piece-by-piece basis. If the requirements are not met, these valves shall not be used. (3) The valves of the following pipelines shall undergo shell pressure tests and sealing tests one by one; those that fail these tests shall not be used: A. Valves for pipelines transporting highly toxic fluids, toxic fluids, or flammable fluids ； B. Valves for pipelines carrying non-flammable, non-toxic fluids with a design pressure greater than 1 MPa, or a design pressure of 1 MPa or less and a design temperature of less than –29°C or greater than 186°C. (4) When applying the SH3501—2002 standard, before installing the valves, each valve body shall be subjected to a hydraulic test. The hydraulic test pressure should be 1.5 times the nominal pressure; if no leakage occurs after holding the pressure for 5 minutes, the test is considered successful. Valves with an upper sealing structure shall have their upper seals tested individually, using a test pressure of 1.1 times the nominal pressure. During testing, the upper sealing surface should be closed and the packing gland should be loosened; it is considered successful if there is no leakage after the pressure is released for 4 minutes. (5) For valves of pipes conveying non-flammable and non-toxic fluids with a design pressure of less than or equal to 1 MPa and a design temperature ranging from –29 °C to 186 °C, 10% of each batch shall be sampled, with a minimum of 1 valve, to undergo shell pressure testing and sealing testing. If it fails the inspection, random checks are conducted twice more; if it still fails, those valves shall not be used. (6) For the pressure test, upper seal test, and high-pressure seal test of the shell, the test medium can be air, inert gas, kerosene, water, or a non-corrosive liquid with a viscosity not higher than that of water; for the low-pressure seal test, the medium can be air or inert gas. When water is used as the test medium, rust inhibitors may be added; the test medium should be clean water, and the chloride content in the water used for testing stainless steel valves must not exceed 100 mg/L. (7) For valves with a steam jacket, the jacket portion shall be pressure-tested at 1.5 times the steam operating pressure. 2. Adjustment tests for safety valves, pressure relief valves, and steam traps. (IV) Storage of valves: Valves should be stored in indoor warehouses, with their open ends protected by covers, and they should be stored separately according to their specifications, models, and materials. Titanium materials, non-ferrous metals, and ultra-low carbon stainless steel valves that are not allowed to be contaminated by iron should be stored separately. The exposed valve stem should be coated with rust-proof grease for protection. Except that plastic and rubber sealing surfaces are not allowed to be coated with rust preventive grease, the closing parts and sealing surfaces of other valves should be coated with rust preventive grease. The interior of the valve, the flange sealing surfaces, and the bolts should be coated with an anti-rust agent for protection.

Generally, that’s not done; water-driven tests and pressure tests can both be used to detect leaks

Follow the specifications: for ordinary pipes, a 5% sealing test is required, in addition to testing as specified by the client

If your company is willing to go to the trouble of conducting pressure testing, it’s possible to have the valve manufacturer provide you with the relevant pressure test reports as proof! :)

Suppression is required; also remember to request a suppression report regarding the water pressure. A pneumatic test is a leakiness test, while a hydraulic test is a strength test. Search the internet for relevant information.

All reputable valve manufacturers conduct a certain proportion of tightness tests on their products before they leave the factory. It can be used right away, basically.

Some manufacturers produce products of very poor quality; it is best to conduct pressure tests. It’s a bit more troublesome in the initial stage, but it’s better than having to carry out repairs repeatedly later on. Moreover, if leaks occur in certain areas, the consequences can be severe.

It needs to be suppressed, and after that the valve should be checked again; in particular, the packing must be tightened once more. Many valves come with such installation instructions. Sometimes it’s not due to quality issues, but rather timing problems; the valve has been produced for a long time by the time it arrives at the site. To some extent, both the packing and the material of the valve body will exhibit signs of fatigue resulting from that prolonged period, so it is necessary to conduct another pressure test to check. This post was last edited by leonnie on 2009-2-4 17:39]

Suppression is necessary. The new valve must be pressure-tested before installation. Pressure testing of the valve body, as well as pressure testing of the valve cover, gaskets, and other sealing elements, is required. A hydrostatic test is better, as it is safer. This post was last edited by daqing01 on 2009-2-4 20:43]

The most important thing is still the inspection of the material used for the components. Whether compression is applied or not depends on where the valve will be used, as well as the qualifications and management level of the supplier. The least reliable option is to purchase from an agent. This post was last edited by CHEN333 on 2009-2-4 at 20:53.]

For new projects, before installing the valves, all of them must undergo pressure testing to ensure their quality and sealing performance. A hydrostatic test is generally sufficient.

I fully agree with the construction of new projects; before installing the valves, it is necessary to conduct pressure tests on all of them to ensure their quality and sealing performance. But those in charge of suppression simply don’t understand the purpose of doing this; otherwise, they should be the ones to “plug the gaps” during maintenance due to leaks that occur during operation!

For new projects, it is advisable to conduct pressure tests on all valves before installation, usually hydraulic tests. Although hydraulic and airtight tests will be carried out after the project is completed, leaky pipes are easy to weld, while replacing valves is rather troublesome, especially larger valves.

It needs to be done; when conducting a hydrostatic test, attention should be paid to venting the air (that is, the sequence of applying pressure – it is generally recommended to first test for tightness and then for strength, but I believe it’s better to first test for strength and then for tightness). After the strength test, releasing the pressure and closing the valves ensures that no gas remains inside the valves, which allows the test pressure to be maintained throughout the process, enabling the test to be completed in one go. But be sure the water quality is clean, and close the valves tightly when shutting them. Be careful with air pressure.

The pressure testing for new pipeline projects that we carry out applies only to the pipelines, not to the valves. According to standard requirements, it is best to conduct pressure testing on valves at the manufacturer’s facility, with the owner’s inspectors overseeing the process on-site. After all, the manufacturer has more advanced testing equipment and more skilled operators, which also helps to save the owner time and money while ensuring that the project stays on schedule

We usually conduct pressure tests on valves before installation, as the valves available these days are really unreliable.

Pressure testing must be carried out before installation, but it is necessary to determine whether hydraulic or pneumatic testing is required. For valves used in low-temperature conditions or for special purposes, hydraulic testing should not be used, as this could cause the packing to become frozen and jam the valve, or lead to chemical reactions with water that might contaminate the fluid. Additionally, for valves that are to be pressurized, they need to be opened and closed several times before pressurization is applied to test the sealing of the valve ports.