Consolidated Pop Safety Valves 1910 Author:Various Introduction THE Consolidated Safety Valve Company has within the last two years inaugurated two exceedingly important movements in the safety valve practice of this country movements which are causing universal modifications of design, and, for the first time in the history of engineering, are putting the methods of safety valve rating and spec... more »ification upon a sound basis. This has, of course, required exhaustive testing and research, in conducting which this Company has spared no expense, deliberately adopting the policy of giving the results freely to the engineering public. This policy has obtained for the Company in this work the co-operation of railroads, of station- ary and marine interests, and of eminent engineers, adding much to the broad application and value of the results obtained. The movements referred to are first, for the rating and specifying of safety valves according to their actual relieving capacities and, second, for increasing their efficiency by modifications in design which make possible the obtaining of larger capacities, and a cleaner, more positive action. .X ITY y Safety Valve Capacity J account of certain of the elaborate tests and extensive research work, conducted by this Company, showing the apparatus A developed, the methods employed and results obtained, has been published in a pamphlet entitled Safety Valve Capacity, which will be sent upon application to anyone interested in this subject. Because of this supplementary publication, the following account of the work will be brief. The function of a safety valve is to prevent the pressure in the boiler, to which it is applied, from rising above a definite point to do this automatically, and under the most severe conditions which can arise in service. For this the valve, or valves, must have a reliev- ing capacity at least equal to the boiler evaporation, under these con- ditions. If it has not this capacity, the boiler pressure will continue to rise, although the valve is blowing, resulting in strain to the boiler and danger of explosion, consequent to over-pressure. Thus, with the exception of a requisite mechanical the most vital factor in reliability, a safety valve is its capacity. Two factors in a safety valve geometrically determine the area of discharge and hence the relieving capacity. These are the diame- ter of the inlet opening at the seat, and the valve lift. The former is the nominal valve size the latter is the amount the valve disc lifts vertically from the seat when in action. The rules for calculating the size of valves to be placed on boilers, which do not include a term for this valve lift, or an equivalent such as a term for the effective area of discharge assume, in their derivation, a lift for each size valve. Nearly all existing rules and formulae are of this kind, which rate all valves of a given nominal size as of the same capacity. To find what lifts valves actually have in practice, and thus test the truth or error of this assumption, that lifts are approximately the same for the same size valve, an apparatus has been devised by us upon which tests of different designs of valves have been conducted. With this apparatus, not only can a valve lift be read, at any moment, to thousandths of an inch, but an exact permanent record of the lift, 189830 3 Consolidated Pop Safety Valves SECTION OF TESTING LABORATORY AT THE PLANT OF THE CONSOLIDATED SAFETY VALVE COMPANY, BRIDGEPORT, CONN. Consolidated Pop Safety Valve PAPER SPOOL CONNECTION TAPPED INTO DIFFERENT PLACES IN VALVE CASE EXHAUST PIPE ETC TO DETERMINE BACK PRESSURE JCE 3-HX ral fittmfI Wyi W------fci-...« less