The pipe fitting standards are divided into the standards of the Ministry of Chemical Industry:

The pipe fitting standards are divided into the standards of the Ministry of Chemical Industry:

　　1, HG/T21634-1990 forged steel socket welded pipe fittings 1/2"-11/2", 3000 and 6000 pounds

　　2, HG/T21635-1990 carbon steel, low alloy steel seamless butt welding pipe fittings DN=50-600mm, PN 25, 40, 64, 100kg/cm2

　　3, HG/T21631-1990 steel seam butt welding pipe fittings DN=300-1000mm

The pipe fitting standards are divided into Sinopec standards:

　　1, SH 3408-1996 steel butt welding seamless pipe fittings DN=15-500mm

　　2, SH 3409-1996 steel plate butt welding pipe fittings DN=200-1200mm

　　3, SH 3410-1996 forged steel socket welding pipe fittings DN=10-80mm

The pipe fitting standards are divided into national standards:

　　1、GB12459-90 steel butt welding seamless pipe fittings DN=10-500mm A, B series

　　2, GB/T13401-92 steel plate butt welding seamless pipe fittings DN=350-1200mm A, B series

　　3, GB/T14383-93 forged steel socket welding pipe fittings DN=15-80mm A, B series

　　4, GB/T14626-93 forged steel threaded pipe fittings DN=8-100

　　5, GB/T17185-1997 steel flange pipe fittings DN=25-600mm PN 2.0, 5.0, 11.0, 15.0, 26.0MPa

Nuts and screws other specifications

Screw specifications: Many of the shops are multiplied by how much, such as M10*25, which is 10MM thick and 25MM long.

　　Nut size: subject to the size of the screw used

　　The size of the spring washer: It is subject to the thickness of the screw used

　　 Screw standard: German Standard (DIN) American Standard (ANSI, ASME) International Standard (ISO) National Standard (GB) Japanese Standard (JIS)

Common sense of nuts and screws

　　Nuts are fasteners with internal threads and used with bolts. They are mechanical parts with internal threads and used with screws to transmit motion or power.

A nut is a nut, which is screwed together with a bolt or screw for fastening. A nut is a part that closely connects mechanical equipment. Nuts and screws of the same specification through the inner thread can be connected together. It is necessary for manufacturing machinery. An original used. There are many kinds of nuts. The common nuts are national standard, British standard, American standard, and Japanese standard. According to different materials, they are divided into carbon steel, high-strength, stainless steel, and plastic steel. According to the product attributes of threaded pipe fittings, they correspond to different national standards. It is ordinary, non-standard, (old) national standard, new national standard, American system, British system, and German standard.

Screw diameter: Generally, the diameter of a screw refers to the thickness of the threaded part. In the production and national standards, the thickness has a tolerance, such as 11.7MM 11.8MM 11.75MM 11.5MM, which all belong to 12MM screws, 9.7MM 9.75MM 9.68 MM and so on all belong to 10MM screws, and so on.

　　 Screw length: Generally, flat head and countersunk head screws are calculated according to the total screw length, and the length of other hexagonal head, round head, and internal hexagonal head is not connected to the head, which is calculated according to the length of the screw.

www.superbheater.com