Straight Length Copper Pipe

Copper has a coefficient of linear expansion of 17 x 10-6oC. for example, a 10-metre length of copper pipe carrying hot water at 600C will increase in length by almost 7mm when heated from 200C. Assuming that the temperature cycling of the system is 200C, there will be a continuous cycle of expansion and contraction of 3.4mm. Refer to table below.

Copper pipe installations have been tried and tested over many years of use in all parts of plumbing and heating systems. Copper’s versatility in such a wide variety of situations has resulted in the design and development of many different types of fixing clips and bracketing systems.

All pipework systems must be adequately supported if they are to give trouble-free service, especially over the long life of a copper system. Manufacturers’ catalogue illustrate a vast range of clips and brackets to meet specific requirements, a few of which are illustrated in Figure 1.

The recommended intervals are set out in Table 1. Studying the table will show that fewer supports are required on vertical runs. This is because the vertical tube will not be subjected to possible sagging between supports. Excessive sagging will occur on horizontal runs of pipes made from any material if the supports are too far apart.

On long runs of tube with fixing supports such as hanging brackets anchor bracing should be used at 12m centers to avoid swaying. The distance between anchor fixings used for bracing and expansion joints in hot water lines is determined by the type of expansion joint used and the amount of movement which the joint can accommodate. Figure 2 shows how a long run of tube can be anchored by means of supports at each change of direction. The expansion can then be accommodated by an expansion joint or by fabricating an expansion loop, either from fittings or by bending the tube. If an expansion loop is used it should be installed and supported in the horizontal plane to prevent air locks.

Notches and holes in simply supported floor and roof joists should be within the following limits:

• Notches should be cut no deeper than 1/8 of the depth of the joist.
• They should not be cut closer to the support than 0.07 times the span, nor further away than 1/4 of the span.

Drilled holes should be no greater in diameter than 1/4 of the depth of the joist. They should be drilled on the neutral axis and should be not less than 3 diameters apart, measured from center to center. Holes should be located in the area between 0.25 and 0.4 times the span of the joist from the support.

Note: Notches or holes for pipes must NOT be cut in roof rafters. Figure 4 shows the permitted limits of notches and holes in floor and roof joists.

Where straight lengths of half – hard copper tube are required to be run in floors they can be laid in notches. By using pipe joist clips with integral protective metal plates, the risk of damage due to punctures from nailing accidents should be eliminated. Furthermore, the rectangular shape of the joist clip can be used as a template when notching joists. This should avoid the joists being weakened accidentally by excessively deep notches.

Although unseen when the installation is complete, joist clips improve the overall quality of the installation. They do this by helping to align the tube and permit expansion movement due to temperature changes in hot water lines. This will help to prevent clicking noises and the water hammer which can arise due to badly-aligned pipework.

All our copper pipes are manufactured to BS EN1057, ISO 9001, and kitemarked

1,000kgs of copper tube for FOC (approx. £6,000 ex VAT in value)

A large proportion of copper for our products, including our 15mm pipe, is mined in Chile. There are around 30 processing plants and factories around the world with a variety of capabilities; we have two drawing plants based in the UK.