1. All pipe is to be made of a long hole surrounded by metal or plastic centered around the hole.

2. All pipe is to be hollow throughout the entire length – do not use holes of different length to form the pipe.

3. The ID ( Inside Diameter ) of all pipe must not exceed the OD ( Outside Diameter ) – otherwise the hole will be on the outside.

4. All pipe is to be supplied with nothing in the hole, so that water, steam or other stuff can be put inside at a later date.

5. All pipe should be supplied without rust; this can be more readily applied at the job site. NOTE: Some vendors are now able to supply pre-rusted pipes. If available in your area, this product is recommended, as it will save a great deal of time at the job site.

6. All pipe over 500ft ( 150m ) in length should have the words "LONG PIPE" clearly painted on each side and end, so the contractor knows it’s a long pipe.

7. Pipe over 2 miles ( 3.2 Km ) in length must also have the words "LONG PIPE" painted in the middle, so the contractor will not have to walk the entire length of the pipe to determine whether it is a long pipe or a short pipe.

8. All pipe over 6ft ( 1.83m ) in diameter must have the words "LARGE PIPE" painted on it, so the contractor will not mistake it for small pipe.

9. Flanges must be used on all pipe. Flanges must have holes for bolts, quite separate from the big hole in the middle.

10.When ordering 90 or 30 degree elbows, be sure to specify left-hand or right- hand, otherwise you will end up going the wrong way.

11.Be sure to specify to your vendor whether you want level, uphill or downhill pipe. If you use downhill pipes for going uphill, the water will flow the wrong way.

12.All couplings should have either right-hand or left-hand threads. Do not mix the threads, otherwise as the coupling is being screwed on one pipe, it is being unscrewed from the other.

13.All pipes shorter than 1/8in ( 3mm ) are very uneconomical in use, requiring many joints. They are generally known as washers.

14.Joints in pipes for piping water must be water-tight. Those for compressed air, however, need only to be air-tight.

15.Lengths of pipes may be welded or soldered together. This method is not recommended for concrete or earthenware pipes.

16.Other commodities are often confused with pipes. These include: conduit, tube, tunnel and drain. Use only genuine pipes.

17.Scottish Regiments in the Army use Army pipes in unusual ways. These are not approved of in engineering circles.