Phenomena: Cold and hot water pipes, air conditioning and ventilation pipes, water supply and drainage pipes collide with each other during installation. Moreover, the contradiction between the pipeline and the decoration and structural beams also occurs from time to time.  It is often the first pipeline to be installed, which is very convenient to construct, and the second pipeline to be installed is very difficult to construct.  It is forced to install on the wrong place or elevation, which affects the quality and even cannot be used, resulting in partial rework.

Reason: The coordination of different types of work is not good at the design stage, the designers lack construction experience, and the reserved clearance is too small.  Before drawing, comprehensive proofreading was lax.  The construction and installation units, each competing for its own progress, will not consider the overall situation.

Countermeasures:

1) For complex civil buildings, in the design stage, each type of work (HVAC, water supply and drainage, power supply and lighting, and construction) shall first negotiate the space separation and determine the elevation range of each pipeline.  Under normal circumstances, one cannot go beyond the limits set for oneself.  In case of any individual section crossing the border, it shall negotiate with other projects.

2) The principle of solving the collision and coordination of various pipelines is generally: "small tubes avoid large tubes, and pressure avoids no pressure".  For example, if the tap water pipe collides with the air pipe, the tap water pipe should turn.  If the cold and hot water pipes collide with the downcomer, the cold and hot water pipes shall be changed.

3) Before construction, the engineer of the equipment manager will draw the pipelines and single lines of each type of work on a plan.  One color pen for each type of pipe.  Integrate the elevation at each intersection point to see if there is any contradiction, find it in time, and solve the problem before installation.

4) In order to reduce investment, save space and reduce floor height, some pipelines without slope requirements can be laid through beams (such as tap water pipelines, fire sprinkler main pipes, etc.).

5) Basic Methods of Pipeline Laying

(1) the pipeline conveying flammable and combustible gases shall not be laid in the same trench as other pipelines.

(2) cold and hot water pipelines and steam pipelines must be insulated.

(3) the distance between the outer wall of the pipeline (or the outer surface of the insulation layer) and the wall or trench wall shall not be less than 0.15m, the distance between the column and beam may be 0.05m, and the distance between the outer wall of various pipelines (or the outer surface of the insulation layer) shall be 0.1~0.15m m.

(4) the distance between the outer wall of the air duct and the wall should be 0.2~0.3m ..  The smaller section uses a small distance and the larger section uses a large distance.

(5) when the pipelines are laid in the same ditch or in the same rack, the cold and busy water pipes should be on the top and the water supply and drainage pipes should be on the bottom, and the water supply pipes should be on the top of the drainage pipes.

(6) When the air pipe and water pipe pass through the floor slab, the size of the reserved hole is as follows: the hole without heat preservation air pipe is the air pipe size plus 100mm, and the heat preservation air pipe is the air pipe size plus 150mm;  The hole of the non-insulated water pipe is generally two sizes larger than the pipe diameter, while the remaining hole size of the insulated water pipe is the pipe diameter plus 150 mm.