1. galvanized pipe fittings: generally DN 15( 1/2 "), 20(3/4"), 25( 1), 32( 1 and1. Name: inner wire elbow, inner wire straight-through, outer wire straight-through, reducing head, positive tee, reducing tee and flange.

2. Clamping parts: generally DN65-DN200. (Design stipulation: clamp is only used for pipes with DN 100 and above) Name: grooved elbow and tee. Rigid fixture. Slotted concentric reducer. Groove reducing tee, reducing tee and positive tee. Mechanical tee (thread). Reducing tee and cross are also divided into thread type and groove type. Short pipe flange, threaded connecting flange, flange pipe clamp.

3. The commonly used fire-fighting pipeline specifications are DN25, DN32, DN40, DN50, DN70, DN80, DN 100, DN 125, DN 150 and DN200.

Extended data:

The specification of fire-fighting pipeline is expressed by nominal diameter DN, not DH.

(1) The nominal pressure pn is less than or equal to1.0 MPa, and the fire-fighting pipeline adopts galvanized welded steel pipe for low-pressure fluid transportation, with the following wall thickness:

DN65, wall thickness s = 4.0mm；DN80, wall thickness s = 4.0mmDN 100, wall thickness s = 4.0mm; DN 125, wall thickness s = 4.0mm；; DN 150, wall thickness s = 4.5mm GB/t 309 1-2008, the maximum specification of galvanized steel pipe is DN 150.

(2) When DN > 150, seamless steel pipe (GB/T8 163-2008) with DN200 and wall thickness of S = 7.0 mm should be used to transport fluid; (Seamless steel pipes are usually expressed by multiplying the outer diameter by the wall thickness, so the pipe is expressed as D2 19×7, and D2 19×7 belongs to the specification series of nominal diameter DN200) DN300, and the wall thickness S = 8.0mm (then the pipe is expressed as D325×8, which belongs to the specification series of nominal diameter DN300).

References:

Baidu encyclopedia-groove pipe fitting