Double-ended Handles are important components for Automotive checking fixtures.
Go no go gauges, also come in both non-threaded smooth variety, such as a pin gauge, or threaded versions which check threaded connections. The benefit of go no go gauges is the ease of use – they require very little skill or interpretation to use correctly. Double-ended handles have many standard specifications in stock. Pin Gauges will be installed in two sides. Green side is Go Pin, red side is NOGO Pin.
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Keywords: water supply pipe U-PVC pipe I. INTRODUCTION With the development of urban construction, the improvement of people's living standards has put forward higher requirements on the quality of drinking water. At the same time, in order to ensure the water quality of the water supply network, the State Ministry of Construction, Ministry of Chemical Industry, China National Light Industry Council, State Building Materials Bureau, China Petrochemical Corporation jointly issued a document and Shaanxi Provincial Department of Construction, Shaanxi Provincial Bureau of Quality and Technical Supervision, Shaanxi Provincial Administration for Industry and Commerce Bureau jointly issued by the Shaanxi Provincial People's Government [2001] No. 247 water supply pipe is strictly prohibited galvanized steel pipe, gray cast iron pipe provisions eliminated.
Division I through the investigation and analysis of water quality, combined with the actual situation of the pipe network, gray cast iron, especially galvanized steel pipe is one of the main water quality and quality of water, at the same time due to gray cast iron, galvanized steel pipe wall scaling Water capacity decreases, increasing water resistance, a serious threat to water safety and reliability.
Second, the promotion and application of U-PVC pipe Currently on the market for a wide range of plastic pipes for water supply, all kinds of plastic pipes have their own advantages and disadvantages, therefore, must be combined with the actual selection of suitable plastic pipe. To this end, I set up a new Secretary for the selection of the leading group of specialized agencies, after investigation and repeated demonstration, the development of the basic principles of the selection of new pipe:
1, complete technical regulations, product standards and design, construction and acceptance of a full range of norms;
2, complete pipe specifications, pipe fittings specifications, complete categories;
3, easy to construct, easy to operate, no special tools, fast and reliable;
4, easy to take over the branch, not quite enough water to open the tee branch pipe 5, easy maintenance, repair methods are simple, repair fittings complete;
6, pipe from sewage, industrial waste water and all kinds of harmful gases such as corrosion;
Combining the above several basic principles, we conscientiously analyze the products of many manufacturers in the market, and refer to the successful experience of other water companies and the problems in use. According to the actual situation of the enterprise, we determine that U-PVC pipes are used as gray cast pipes and galvanized U-PVC pipe has the advantages of light weight, no rust, no fouling, smooth inner wall, superior hydraulic conditions and no pipeline secondary pollution. Compared with other plastic pipes, U-PVC pipe is technically mature , Pipe, fittings complete specifications, easy maintenance, and the successful use of the practice, I confirmed the Secretary to promote the use of U-PVC pipe and issued "on the process of stopping the use of galvanized pipe and gray iron pipe in the water supply pipe to promote the use of New pipe notice. " Taking into account the current production of many U-PVC pipe manufacturers, pipe fittings GM is not very good. Division I determine the three manufacturers of products as a trial of pipe.
In addition, with a variety of U-PVC connection, the actual working practices of construction workers, clear DN200, DN100 U-PVC pipe connector selection rubber ring connection. DN50, DN25 use U-PVC pipe joints live joints and joints inserted plastic adhesive.
Third, the application of a few experience U-PVC pipe as a buried water supply pipe, the application in the country for several years, compared to the Division I use later, after a period of use, is now put forward some of the applications Experience:
1, trench excavation and backfill.
Compared with ductile iron pipe and steel pipe, U-PVC pipe is light weight, easy to install, less labor, less demanding on construction equipment. It is based on the above characteristics, construction, the construction unit to save costs, trench excavation width sometimes fail to meet regulatory requirements, such as sometimes DN200 trench width of 0.6-0.7M. Although not affect the pipeline installation, but the backfill quality is difficult to guarantee, the soil compaction can not be guaranteed. Especially with the construction of road construction at the same time, generally more for the road repair unit after the lime soil, pipe trench excavation, the general depth of about 1.7M pipeline design, the actual need to dig about 1M, trench Narrow and shallow, difficult to meet the requirements of backfill, pavement in real time, it will threaten the safety of the pipeline will also affect the quality of road works.
In addition, the ditch bottom should ensure that the thickness of not less than 100MM sand cushion, especially in the old city, ditches more construction waste, we must strictly enforce the norms to ensure the quality of backfill so that the pipeline can run safely.
2, pipe installation U-PVC pipe than the metal pipe is less important. The installation requires less manpower and lower installation cost. The connection mode adopts the rubber ring interface, which greatly improves the installation efficiency. The larger the diameter is, the more obvious the superiority is. The only downside is that the pipeline port no jacking depth mark line, inconvenient to grasp the jacking depth when installing, especially at night installation. Its impact is even greater. In addition, pipe often need to cut the pipe installation. Notched face must be serious, especially when crossing over other underground facilities, due to U-PVC elbow mostly double socket, different from the straight line installation. If the groove is not in place, it is difficult to install, but also easy to top the apron or dislocation of the apron, such as in a pipeline project, the pipeline need to cross the power ditch, due to pipe cutting end bevel not in place, uneven Nearly two hours also can not advance, after re-groove, successfully installed successfully.
3, the pipeline pressure test pipeline pressure test, hydrostatic pressure hydrostatic pressure test specifications must not be designed within the water pressure, and shall not be less than 0.8Mpa. Division I follow the metal pipe test standards, the test pressure of 1. OMPa, the regulator 0.5h, U-PVC pipe axial expansion coefficient larger than the metal pipe, our standard pressure test more standardized, the pressure test interface generally prolapse 2-5MM, so the pressure test backfill must be achieved Required compaction, pipe pier to achieve the design strength, back safe and stable, at the same time, observe the pressure when the interface to ensure smooth pressure test to ensure project quality.
4, the pipe pier as a water supply pipe, U-PVC pipe has been used for some time, but the relevant standards are not complete, such as the pipe pier practice, metal tube village pier has a relatively complete standard atlas, construction workers on The practice of metal pipe is familiar with, in practice, construction workers often by metal pipe pier practice masonry U-PVC tube village pier, and U-PVC pipe and metal pipe material characteristics are very different, should be different analysis, specification Clearly stipulates that "U-PVC pipe shall not be used 360 °" full of concrete for foundation treatment or to enhance pipe carrying capacity. "To avoid pipelines due to local stress concentration and damage to the pipeline, affecting the safe operation of the pipeline, therefore, I Division with the norms and local soil Characteristics of the pier masonry has been standardized, developed a construction standard, standardize construction, to ensure project quality.
5, the user pipe installation User pipe installation, due to U-PVC material meter wells without the appropriate installation standards, most of the installation reference to the implementation of the existing national standard metal pipe atlas. Due to U-PVC and metal pipe material is different, prone to some problems:
5.1 water meter pipe more, especially in the bypass table, the construction of pipe diameter DN> 100 pipe fittings are generally rubber ring connection and flange connection of two. The use of rubber ring interface, due to the vertical and horizontal directions are a total distance between the wall with the table a certain distance, the water test, there will be off the pipe (Xi'an water supply network average pressure 0.24MPa or so), and flange connection This phenomenon does not appear, combined with the construction practice, water meter pipe connection flange connection than the apron connection safety.
5.2 The price of U-PVC pipe fittings is higher than that of other metal pipe fittings. Taking the water meter with diameter DN200 and bypass pipe diameter DN100 as an example, the cost of main tree of U-PVC pipe fittings is more than double that of ductile pipe fittings, Affect the enthusiasm of the construction unit application, thus reducing the price of pipe fittings, U-PVC pipe to better promote.
5.3 When installed according to the existing water meters and standard atlas, the pipes and fittings inside the common water meter are in a vacant state. The sluice piers, tee joints and the elbows at the gates and water meters are used to construct the piers. At present, U -PVC pipe water meter and there is no clear specification requirements. Actual operation, sometimes under the maintenance and repair, not supporting the pier will affect the maintenance of pipe installation. Raw water meter and standard atlas are based on the characteristics of metal materials, and U-PVC pipe and metal pipe are very different, should be combined with U-PVC material characteristics, make the appropriate changes in the water meter and the tee, elbow at the masonry Support pier or take reinforcement measures is to ensure the safe operation of pipelines effective measures.
Combined with the experience of construction practice, to promote the use of good U-PVC pipe, according to the national standards, norms, combined with the characteristics of enterprises to develop enterprise design rules, construction standards, acceptance criteria. At the same time do a good job in training, better promote U-PVC pipe.
Fourth, the concluding remark U-PVC pipe as a new type of urban water supply pipe, with its advantages in the water supply project is increasingly widespread in the production practice also needs to continue to further improve and perfect the technical specifications and related standards for U-PVC water supply pipe to promote greater contribution to the promotion. The above is the author in the construction practice for the Association, deficiencies, hope colleagues correct. (Xi'an City Water Company Kong Fan Tao Guo Xin Chao)
Abstract: The application of U-PVC pipe in water supply pipe is introduced. Combined with construction practice, some experiences of application of U-PVC pipe are introduced.