CEMENT-LINED PIPES

Wairarapa Times-Age, 19 April 1940, Page 4

CEMENT-LINED PIPES

IMPROVING MASTERTON’S WATER SUPPLY SOME ADVANTAGES OUTLINED. REMOVAL OF INCRUSTATION The proposal to concrete-line Masterton water-mains, which is to be submitted to a poll of ratepayers, is of some importance to the town. The necessity for some protective in iron or steel water mains, in addition to the usual treatment with Dr Angus Smith’s solution, has long been acknowledged; but nothing really effective has been evolved until recent years, when concrete-lining, either centrifugally, or by the more recent process of lining in situ known as the Tate Process —became practical solutions to the problem. The incrustation in metal pipes is due to the presence of humic acid or iron bacteria in the water to be transported, and is particularly evident in soft, or peaty waters. It may also be brought about by electrolysis. That this problem of incrustation and L.tuberculation can definitely be elimin- r ated at a very reasonable cost is proving a great boon to local authorities, and is being availed of by a great number of them in this country and elsewhere.

The natural affinity of concrete for iron or steel, makes the lining of pipes with concrete an ideal process; and. once it has matured, the two cannot be separated, except by destruction. It has been, proved, and conclusively, that while the lining does add materially to the strenth of the pipes, it does not increase the rigidity; and that when deflection does take place in a length of pipe, the lining bends with it, and without cracking; also, the pipes can be drilled or cut with ease, and without shelling. QUESTION & ANSWER COLUMN. 1. Q. Why is is proposed to line the 10, 12 and 18-inch mains? A. Because they have become heavily incrusted, reducing the flow by approximately 30 per cent, after having been in use for 40 years. 2. Q. Will they corrode-up and become heavily incrusted again, after lining? A. Definitely no; once lined, the bore remains the same throughout the life of the pipe. 3. Q. Is it necessary to lift the pipes to cement-line them? A. No; by the Tate Process which it is proposed to use, the pipes are lined in the ground; thus saving the cost of lifting and relaying. 4. Q. Wouldn’t it be satisfactory to just clean the mains by scraping? A. No; the full effect of just cleaning, only lasts for about two or three years; and it is found that the growth of the tuberculation and incrustation is much more rapid, after cleaning. 5. Q. Has the cement-lining of water mains been carried out in any other towns in New Zealand? • A. Yes; nineteen towns in New Zealand have had cement-lining carried cut-in 3in. to Bin. mains: _ ly 95 miles having been completed t«W date. 6. Q. Are they entirely satisfied with the results obtained? A. Yes; entire satisfaction has been expressed by them all; and they hope to extend the work, as soon as finances permit. (To be continued.)