GAS PRESSURE

Manawatu Standard, Volume LVII, Issue 197, 21 July 1937, Page 14

GAS PRESSURE

CITY’S GROWING NEED.

CONTROL OF MAINS

“You will note that the output of gas from the works when compared with that of June of last year has increased by over one million cubic feet. This is equal to 12£ per cent. To obtain this increased output from the works it was found necessary to use approximately 30 per cent, of Newcastle coal. The Mond gas plant at the power station has now.been started up to assist the Glover West plant, so that the necessary laying off and scurfing of the Glover West retorts may be carried out as required.” This statement was made by the manager of the gas department (Mr J. W. Muir) in his report to the Palmerston North City Council on Monday. “Regarding the request for my report on the prospects of increasing the pressure of gas in College Street West, and whether any reduction will eventuate in view of the erection of houses in that area under the Government housing scheme,” the manager added, “firstly I must state that in my opinion the building of extra houses in the Cook Street area will not have much effect upon the gas pressure in that area, because Cook Street is fed with a six-inch main across the railway to Church Street, and a four-inch main exists in Cook Street from Church Street to Park Road. There is only a two-inch main in College Street from Batt Street to Botanical Road. No doubt this will eventually have to be replaced with a larger main, but I do not think this is necessary at the present time. The main trouble regarding pressure is due to the size of the main from the works to Albert Street. Although it is 70 chains from Albert Street to the Square, only 2-10 ths of an inch pressure is lost, whereas for the 110 chains from the works to Albert Street 48-tenths of an inch pressure is lost. This shows that this main is far too small under the present supply conditions, and the position will, of course, become worse on the present increasing consumption. “The solution would be to extend the 18-inch main from Albert Street to the works —this would cost something in the vicinity of £IO,OO0 —or to instal a high pressure main from the works to town, in addition to the existing low pressure 12-inch main. I put forward another solution for consideration, this being to instal a booster at the works, and boost the gas through the existing 12-inch main to Albert Street during peak load hours, so as to deliver gas to the 18incuh main through a reducing governor at a constant pressure of. approximately 50-lOths.; also to instal reducing governors on the branch mains at Brightwater Terrace, Fitzroy and Ruahine Streets, so as to maintain a constant pressure of 40 to 50 tenths at these points. This .would enable pressures of 40 to 50 tenths to be maintained on the mains reticulation of the lown, without increasing the pressure in the Terrace End area to a figure in excess of a safe reasonable working pressure. “The cost of doing this would be small in comparison with the £IO,OOO for an 18-inch main. We already have in stock a 12-inch steam turbinedriven booster at the works. This came out of the old Cook Street works, and is almost a new machine. I understand it was in use for only about one month in the old works, prior to these being closed down when the new works were completed. The governors required at Brightwater Terrace and Fitzroy Street are only small 4-inch governors and the one at Ruahine Street is 8-inch. The governor between the 12-inch and 18-mch mam would be the greatest expense. “I am unable to give definite figures of the cost of the scheme outlined above, not having definite figures a,: to the cost of suitable governors, hue 1 estimate the total cost will be quite a small figure, somewhere m the vicinit of £SOO ** ✓ 1 The council .decided to obtain quotations for 4in., Sin., 12m., and 18m. governors.