- Before the ditch is dug, obstacles on the digging area should be cleared away.
Ensuring that the soil can be backfilled sufficiently to the area below the pipes for the future backfill should be taken into account. More space of the ditch should be kept at pipe joints in order to operate easily.
Except for special situation, the verge of the ditch should be a straight line and the bed should be on the same level. When dug by mechanical method, 0.2-0.3m soil layer should be remained for manual operating.
- Dimensions of the ditch (without steel plate stage).
- Using a wire brush and a clean rag, carefully clean the inside of the socket particularly the gasket recesses. In particular, remove any deposits of earth, sand, etc. also clean the spigot of the pipe to be jointed and the gasket itself, get smooth edge.
- For ductile cast iron pipe typed DN100~300mm, insert folded gasket into the socket end to make brake facing block embed tightly in the base, Press the protrude of gasket till the gasket fixed evenly in the socket. For pipe typed above DN400mm, bend two ends of the gasket, then press two protrudes outwards one by one, thus more easily insert the gasket into the base. The internal face of brake facing block can’t be extend from the brake of the socket. Check the gasket proper or not in respect of the right figure.
- Lubricate interface of gasket and spigot end. Lubrication could be soap water or nonpoisonous alkaline lubrication.
- Insert spigot into socket till touch gasket at the same axle. It must be straightened properly to make the central axle of pipe or fittings coincide. While connecting pipe, different pipe adopts different tools. Insert pipe carefully and continuously, if existing larger resistance force, pipe connection should be stopped immediately then draw out the pipe and check the position of rubber gasket and socket and spigot end. After removing troubles, insert again. The insert depth required should be between two white lines.
- Insert straight scale into the circular space between socket and pipe wall till touch the rubber gasket and measure the depth even or not along pipe’s cycle. Check the pipes connected with each other whether along the same axle, otherwise the ditch bottom should be adjusted to make irregularity even.
- After finish assembling joint, in respect of diameter adjust angular deflection which should satisfy the requirements mentioned in the right list.
- Backfill: Generally, pipeline needed testing should be tested water pressure after all backfilled, in particular, the joints could be not backfilled, but the middle part of pipe should be backfilled completely for avoiding pipe movement prior to testing. It is not essential to select earth for backfilling, whereas the part touching with the pipe directly had better select sand or fine earth while excavating. Attention that at the both sides of pipeline should all be filled with sand, same as the pipeline bottom, in particular try to exhaust groundwater and avoid the pipeline subsiding after installation.
Post time: Apr-16-2021