Pipe cap, plug, also known as head covering, pipe cap, stop. Cap is the purpose of the welding outside the pipe end or loading pipe thread on to cover wall pipe fittings. Cap is used for sealing the pipe, tube cap effect is the same as the tube wall. And blind plate form to use, the difference is blind plate can be removed, and the cap is welded on the pipe, tube cap is not detachable, pipe cap including convex cap, conical shell, variable diameter section, the design of the flat cover and tighten. Convex tube caps include: dish tube caps, QiuGuanXing cap hemispherical tube, oval tube caps and hats. From the standpoint of stress, convex cap in the gradually from hemispherical tube cap is not good, but look from the manufacturing difficulty, good manufacture gradually. Cap material and other material is the same as the pipe fittings, carbon steel: ASTM/ASME A234 WPB, WPC alloy: ASTM/ASME A234 WP 11-12-1 - WP WP WP 22 - WP5 WP - 91-35 crmov WP911, 15 mo3 15 crmov, stainless steel, ASTM/ASME A403 WP 304-304 - l - 304 - h - 304 ln - 304 NASTM/ASME A403 WP 316-316 l - 316 - h - 316 ln - 316 - n - 316 ti ASTM/ASME A403 WP 321-321 - h ASTM/ASME A403 WP 347-347 - h: low-temperature steel ASTM/ASME A402 WPL3 - WPL 6 high performance steel: ASTM/ASMEA860 WPHY 42-52-60-65-46-65 cast steel, alloy steel, stainless steel, copper, aluminum alloy, plastic, argon luo drain, PVC, PPR, RFPP (reinforced polypropylene), etc. Cap USES: water, beverages, beer, food, petrochemical, nuclear power, chemical fertilizer, shipbuilding, machinery, medical equipment, waterproof processing, pipeline, etc. Splice weld direction when asked to only allow is radial and ring. After large cap may cancel this request. Stitching distance requirements, for more than 3 g, and not less than 100 mm (welding heat affected zone is high stress zone, and in the chemical composition of the area will be a loss. So to avoid the high stress area, the area and thickness. According to the practical experience, the stress attenuation length is greater than 3 g, and not less than 100 mm). But refrigeration equipment is difficult to meet the requirements, has its particularity. Thebutt welds joining together after forming the head, should be 100% rays or ultrasonic testing, the qualified level with the equipment shell. Finally forming the same welding seam detection level, scale and equipment shell, high waste. Example: if the shell is 20% testing equipment, qualified III. The straight stitching and final weld, III qualify, welded joint coefficient is 0.85; If the equipment shell is 100% inspection, II qualification. The straight stitching and final weld is unqualified, II welding joint coefficient is 1 so straight stitching while 100% inspection, but is not the same as the level of qualified, along with the housing. But must pay attention to the process manufacturing process: the right way is: blanking (line) - small board together big board - molding - nondestructive testing if it's wrong to do testing before molding, guarantee the forming after the quality of the products. That is nondestructive testing refers to the nondestructive testing. Cap according to the stress classification for about 17 species, and the pipe standard pressure rating of the United States is the same, there are Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, SCH100, Sch120, Sch140, Sch160, XXS; One of the most common is two kinds of STD and XS. Cap in industrial buildings is not very common, only tube end cap only for use in the pipe used in closed pipes, and the purpose of the blind flange is basically the same, is blind flange installation can be removed, but the cap can be removed, pipe cap is welded on the pipe, and is very close in the form of blind flange.