Water supply and drainage system with the valve test and test
March 24 07:01:30, 2021
Abstract: This paper introduces the commonly used relevant standards in the manufacture and inspection of valves for water supply and drainage systems, and discusses the test items and test methods that should be carried out by different types of valves. 1, Overview Valve products are used in pipelines to control the fluid components, play a diversion, interception, regulation, to prevent backflow and shunt and so on. Valves for water supply and drainage systems are classified according to purpose and function, mainly including cut-off valves (mainly used to cut off or connect media such as gate valves, globe valves, butterfly valves, ball valves and plug valves, etc.), regulating valves Medium flow and pressure, etc., such as regulating valve, throttle and pressure reducing valve, etc.), check valves (to prevent media backflow, such as check valves of various configurations) and exhaust valves (for automatic Exhaust pipe air, such as single-port exhaust valve and dual-port exhaust valve, etc.). Each valve product must be inspected before it leaves the factory. Some valves are also subject to type tests to verify that all their performance or function meets the standards or operating requirements. 2, inspection and test items Common valve type test and factory test should be carried out in the inspection and test items in Table 1 and Table 2, valve type test valve and factory test should be carried out inspection and test items in Table 3 and Table 4. Note: ①<indicates that you need to test or test the project. ② valve sealing structure, to be done on the seal test. Note: ①<indicates that you need to test or test the project. ② valve sealing structure, to be done on the seal test. 3, the valve manufacturing and testing standards for the manufacture and testing of valves to the drainage system in Table 5. Table 5 valve manufacturing and testing standards Standard No. Standard Name Domestic relevant standards GB / T General valve mark GB / T Flanged metal valve structure length GB / T Multi-turn valve drive connection GB / T Universal valve copper Alloy casting technical conditions GB / T General valve gray cast iron technical conditions GB / T General valve ductile iron technical conditions GB / T General valve carbon steel castings technical conditions GB / T General valve austenitic steel casting technology Conditions GB / T General valve Flanged iron gate valve GB / T General valve Iron cut-off valve and lifting check valve GB / T General valve flange and butt welded steel gate valve GB / T Universal valve Flanged steel stop valve and lift check valve GB / T Universal valve steel Swing check valve GB / T Universal valve flange and butt welded steel ball valve GB / T Universal valve flange And the butterfly valve connected to the folder GB / T Spring direct load safety GB / T General requirements for relief valves GB / T Universal valve Swing check valve - GB / T Flat steel gate technology GB / T Iron and copper ball valve GB / T Plumbing internal thread Connecting valve JB valve model preparation method JB / T liquid-controlled butterfly valve only JB / T valve castings appearance quality requirements JB / T General valve delivery requirements JB / T metal butterfly valve seal JB / T ordinary Valve electric device technical conditions JB / T Valve manual device technical conditions JB / T Wafer knife gate valve GB / T General valve pressure test JB / T General valve flow coefficient and flow resistance coefficient of the test method Foreign Related Standards ISO 5209 Industrial valves ISO 5996 iron gate valves ISO 7259 mainly by wrench underground iron gate valve ISO 5208 industrial valves - pressure test valve ISO 10631 general purpose metal butterfly valve BS 5150 general purpose cast iron wedge single Gate or double gate gate valve BS 5151 Cast iron parallel gate valve for general purpose BS 5152 Cast iron stop valve and check valve for general purpose BS 5153 Cast iron check valve for general purpose BS 5154 Copper alloy stop valve for general use, Gate valves BS 5155 Cast iron and carbon steel butterfly valves for general purposes BS 5159 Cast iron and carbon steel ball valves for general purposes BS 5160 Steel shut-off valves for general use, closing 2 Check valves, lifting check valves BS 5163 Gate valves for water supply systems BS 5433 Underground Gate Valves for Water Supply BS 5417 General Industrial Valves BS 5418 General Industrial Valves ANSI / AWWA C500 Water Supply and Drainage Gate Valves ANSI / AWWA C501 Cast Iron Gate Valves ANSI / AWWA C509 Water Supply and Drainage Systems Elastomeric Seat Gate Valves AWWA A504 Rubber Seat Butterfly Valves AWWA A507 6 ~ 48in. Ball Valves AWWA A608 Swing Check Valves for Water Supply Equipment with Nominal Diameter 2 ~ 24in. MSS SP270 Iron Gate Valves with Flange and Threaded End JISB 2031 Gray Cast Iron Valves JISB 2032 Clamp rubber valve butterfly valve JISB 2041 Cast iron 10kgf / cm2 flange connection cut JISB 2042 Angular shut-off valve for 10kgf / cm2 flanged cast iron JISB 2043 Cast-iron gate valve for flanged 10kgf / cm2 flanged JISB 2044 Cast-iron gate valve for flanged 10kgf / cm2 flange connection JISB 2045 10kgf / cm2 Flanged Swing Check Valve JISB 2051 10kgf / cm2 Malleable Cast Iron Straight Thread Connection Stop Valve JISB 2051 10kgf / cm2 Malleable Cast Iron Straight Thread Connection Gate Valve JISB 2051 10kgf / cm2 Malleable Cast Iron Straight Thread Connection Lift Check Valve JISB 2062 Plumbing Gate valve JISB 2064 Butterfly valve for water pipe JISB 2072 Cast iron angle valve for 10kgf / cm2 flange connection JISB 2073 Cast steel gate valve for 10kgf / cm2 flange connection JISB 2074 Cast steel 10kgf / cm2 Flange connection Swing check valve JISB 2081 Cast steel 10kgf / cm2 Flanged shut-off valve JISB 2082 Cast steel 10kgf / cm2 Flanged shut-off valve JISB 2083 Flanged open-stem valve JISB 2084 Cast steel 10kgf / cm2 Flanged Swing Check Valve 4, the quality requirements of the standards on the quality of the valve made the relevant requirements. ①The chemical composition and mechanical properties of the valve body material meet the requirements of the relevant material standards. ② Valve casting shape and size of the deviation in line with the provisions of the drawings. ③ valve casting non-machined surface should be smooth, smooth, non-sticky sand, no scale, no porosity, no sand, no cracks and other defects. The word clearly marked casting, gate and riser flush with the casting surface should be flush. ④ valve parts of the connection should be solid, no loose phenomenon. ⑤ valve pressure test and sealing performance test results in line with the requirements of the test standards. ⑥ valve operation should be in the nominal pressure and the specified pressure conditions, opening and closing operation should be no jamming phenomenon. ⑦ has a certain number of operations and service life. ⑧ greater flow of capacity (that is, through the valve, the pressure loss at the valve smaller). 5, inspection and test methods 5.1 casting quality casting shape and size should be consistent with technical drawings or demand-side regulations. If there is no requirement of size deviation, the relevant provisions of JB / T 2580, GB / T 6414 and GB / T2121 should be taken for the material. Valve parts of the minimum wall thickness, the length of the structure deviation, gate wear and tear displacement margin shall not be less than the product-related technical standards or product drawings requirements. The valve blank and the finished product of the valve should not be cracked, cold-separated, sand-filled or stomatal. The sticky sand, sprue, riser and scale on the casting surface should be removed. The word should be clear. Pressure housing should be 115 times the nominal pressure GB / T 13927 standard shell test, the result should be no visible leakage and no structural damage. The chemical composition and mechanical properties of castings are in accordance with the requirements of GB / T 12225, GB / T 12226, GB / T 12227, GB / T 12229 and GB / T 12230. 5.2 Pressure Test Pressure test is the most basic valve test. Each valve is pressure tested before leaving the factory. Test pressure and duration according to the provisions of GB / T13927 standards, the project test shell test and seal test, the valve seal structure also need to be on the seal test. During the test, the valve should not exert any influence on the test results. Test pressure should be maintained during packing and testing. When using liquid as the test medium, the air inside the valve body should be excluded. The valve should be closed in the manner given by the design. Relevant standards of the test are GB / T 13927, MSS SP61, ISO 5208, DIN 3230, API598, NFM 872401, ANSI B16134, J IS B2003, BS 5417 and BS 6755 and the like. Valve shell test is the valve body and bonnet connection made of the entire valve housing pressure test. Its purpose is to check the tightness of the valve body and bonnet, that is, the pressure resistance of the entire housing including the connection of the valve body to the bonnet. Do not allow valves to be painted or used with other leak-proof coatings prior to shell testing. Check the inventory valve for the user, then no longer get rid of the existing coating. Shell test requirements, the shell, including valve body and valve cover connections shall not occur leakage, may not have structural damage. Seal test is to test the performance of the opening and closing pieces and the valve seal performance test. Sealing test points high pressure liquid seal test and low pressure gas seal test. Before the sealing test, in addition to the oil-sealed valve, the oil on the sealing surface should be removed, but no more than no protective agent should be applied. During the test, the pressure in the specified direction of circulation is applied to the valves that prescribe the flow direction of the medium, and the check valve is pressurized from the outlet (Table 6). Note: For safety valves, control valve test method according to the provisions of the relevant product standards. 5.3 operating torque and life test Some of the foreign standards have developed the maximum operating torque of the valve and the basic number of life, such as BS 5163 and AWWA C509 and so on. In the valve inspection, the valve should check the operating torque. The relevant standards in our country have not stipulated the detailed requirements of operation torque test and life test for general purpose valves (it will be revised with reference to foreign standards), but the working life test procedures for various types of valves have been formulated. 5.4 Flow 2 Pressure Difference and Flow Coefficient Foreign companies attach great importance to the flow of the valve 2 differential pressure and flow coefficient, will be the typical structure of the valve flow 2 differential pressure and flow coefficient test and data available to designers and users, so that In a reasonable choice of pump head and power. With the valve flow 2 differential pressure and flow coefficient data, the user can select the valve with small relative pressure drop and large flow rate, which can reduce losses and save a lot of electricity, and the benefits are very significant. China has also formulated a standard valve flow and flow coefficient measurement methods, carried out various types of valve resistance coefficient test. 6, the conclusion Valve must be carefully in accordance with the relevant standards before the factory, the various tests to ensure its performance and piping system safety.
A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or Chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or Wire Rope as its lifting medium.
The basic hoist has two important characteristics to define it: Lifting medium and power type. The lifting medium is either wire rope, wrapped around a drum, or load-chain, raised by a pulley with a special profile to engage the chain. The power can be provided by different means. Common means are hydraulics, electrical and air driven motors. Both the wire rope hoist and chain hoist have been in common use since the 1800s, however mass production of an Electric Hoist did not start until the early 1900s and was first adapted by Germany. A hoist can be built as one integral-package unit, designed for cost-effective purchasing and moderate use, or it can be built as a built-up custom unit, designed for durability and performance. The built-up hoist will be much more expensive, but will also be easier to repair and more durable. Package units were once regarded as being designed for light to moderate usage, but since the 60s this has changed. Built-up units are designed for heavy to severe service, but over the years that market has decreased in size since the advent of the more durable packaged hoist. A machine shop or fabricating shop will use an integral-package hoist, while a Steel Mill or NASA would use a built-up unit to meet durability, performance, and repairability requirements. NASA has also seen a change in the use of package hoists. The NASA Astronaut training pool, for example, utilizes cranes with packaged hoists.