Installation steps of galvanized steel pipes

1. Cutting the pipe: According to the on-site survey sketch, draw a line on the selected pipe and cut the pipe according to the line.

a. When cutting the pipe with a grinding wheel saw, the pipe should be placed on the grinding wheel saw caliper, aligned with the drawn line, and clamped to cut the pipe. When cutting the pipe, press the handle evenly and do not use too much force. After cutting the pipe, the iron film and burrs on the pipe mouth section should be cleaned.

b. When cutting the pipe with a hand saw, the pipe should be fixed in the pressure clamp of the pressure case, the saw blade should be aligned with the drawn line, and the saw should be pushed with both hands. The saw blade should be kept straight with the axis of the pipe. The force of pushing and pulling the saw should be even, and the sawing should be sawed to the end. It is not allowed to twist or break to prevent the pipe mouth section from deforming.

2. Threading: The cut pipe should be threaded in batches according to the pipe diameter. Generally, a pipe diameter of 15-32mm is threaded twice, a pipe diameter of 40-50mm is threaded three times, and a pipe diameter of 70mm or above is threaded 3-4 times.

a. Use a threading machine to thread the pipe, clamp the pipe on the chuck of the threading machine, leave the appropriate length to clamp the chuck, align the plate sleeve number, install the die, align the scale with the pipe diameter, hold the fixed trigger, align the lubricant tube with the thread head, start the machine to push the plate, and wait for the thread to be sleeved to the appropriate length, and then gently release the trigger.

b. Use a manual threading plate to thread, first loosen the fixed trigger, retreat the threading plate to zero degrees, install the die according to the sequence number, align the plate with the required scale, tighten the fixed trigger, put the pipe in the pressure case pressure clamp, leave the appropriate length to clamp, gently put the threading plate into the pipe to make it moderately tight, then push the threading plate with both hands, put on 2-3 buckles, and then stand next to the threading plate. The force should be even. When the thread is about to be sleeved, gently release the trigger, start the machine to withdraw the plate, and keep the thread tapered.

3. Fitting pipe fittings: Fit pipe fittings to the pipes with threads according to the on-site surveying sketch.

a. When fitting pipe fittings, the required pipe fittings should be brought into the pipe threads to test the tightness (generally, 3 turns by hand is appropriate), apply lead oil on the threads, wrap hemp and bring the pipe fittings into the pipe, then tighten the pipe fittings with pipe clamps to expose 2-3 turns of the threads, remove the hemp heads, wipe off the lead oil, number and place them in the appropriate position for straightening.

b. Choose the appropriate pipe clamp according to the size of the pipe diameter of the fittings

4. Straightening the pipe section: Straightening the pipe section with pipe fittings installed before installation.

a. Apply lead oil on the threads of the pipe section with pipe fittings installed, connect two or more sections, and do not only consider the direction of the reserved opening when connecting but also consider the tortuosity of the pipe. After aligning each other, turn the direction of the reserved opening to the appropriate position and keep it straight.

b. After the pipe section is connected, it is necessary to check whether the pipe diameter, reserved opening direction, and diameter change position are correct according to the planning drawings before straightening.

c. The pipe section should be placed on the pipe adjustment rack or pipe adjustment platform for straightening. Generally, two people are suitable for operation. One person visually inspects the end of the pipe section, and the other person hits the bend with a hammer. While hitting, observe, until the straightened pipe section stops without bends, and mark the connection point of the two pipe sections, remove one or several sections, and then connect another section or several sections until the adjustment is completed.

d. For pipes with too many bends at the connection point of the pipe section or large diameters, you can use a furnace or gas welding to heat it to 600-800℃ (fire red), put it on the pipe rack, and roll the pipe continuously, use the pipe's weight to make it straight, or use a wooden board to pad the heated area and hit it lightly with a hammer to straighten it. After straightening, roll it continuously before cooling, and apply engine oil to the heated area when the temperature is about to reach the right temperature. All threads that are straightened by heating must be marked with numbers, removed, and re-coated with lead oil and hemp, and then the pipe section should be aligned with the marks and tightened.

e. When straightening the pipe section equipped with valves, the valve cover should be removed first, the valve should be padded and then hit to prevent the valve body from cracking.

f. Galvanized carbon steel pipes are not allowed to be straightened by heating.

g. The pipe section is not allowed to be damaged when straightening.