The long cylinder at the bottom of the regulator is a dashpot, the piston of which is connected with the main valve of the regulator, thereby preventing sudden and violent “jumping” of the pump when the pressure suddenly changes. These valves are made in all the pipe sizes; those up to and including 2-inch of the best steam metal; the largest sizes of cast iron, lined with steam metal. The springs are made of the finest tool steel, tempered.
Fig. 634.
The Mason Regulator Co., Boston, are to be credited with the following directions:
The regulator is placed in the steam pipe leading from the boiler to the steam pump and as near the pump as possible. The connection with the water system is made either from the tank or from the water system, at some little distance from the pump. Brass pipe should be used if possible, for this connection. The drip should be connected to some pipe where there is no back pressure. The steam from the boiler enters at the point marked “steam inlet from boiler,” and thence through the passage, X, through the port, which is kept open by the tension of the spring, 79, upon the auxiliary valve, 80. It continues down through the passage, Z, to the under side of the differential piston, 70, and raises the valve, 16, so that the boiler pressure is admitted to the pump through the passage marked “steam outlet to pump.” This starts the pump, which continues in motion until the required water pressure is obtained in the system and acts through the connection marked “water pressure inlet” on the diaphragm, 74. This diaphragm is raised by the excess of water pressure, and carries with it the auxiliary valve, 80, which closes the port for steam pressure. By the closing of this valve, the boiler pressure is shut off through the passage, Z, from the differential piston, 70, and the steam pressure from the boiler immediately closes the main valve, 16, so that no more pressure is admitted to the pump, which remains inactive until the water pressure in the system drops below the normal joint and relieves the water pressure in the chamber, O, which causes the auxiliary valve, 80, to open again, and starts the pump as before described. The check valve, 71, which is placed in the bottom of the piston, 70, allows the pressure regulator to open easily, but stops the pump quickly. This is a great advantage, as the pump will not start with a jump, the moment the water drops. By changing the tension of the spring, 83, through the key stem, 85, the amount of water pressure can be regulated.
Fig. 635.
Mason water reducing valve. Fig. [635] is designed to reduce the water pressure from the street water mains to a low pressure, for houses and buildings. The body or valve portion is fitted with couplings, so that it may be easily attached to a pipe. That part of the valve above the diaphragm, and which comes in contact with the water, is made of the best steam metal, thus preventing corrosion. The long spring case is made of heavy iron pipe, at the end of which is an iron bracket, suitably drilled, so that the valve may be securely bolted either to the floor or to a beam overhead. The tension of the main spring is adjusted by means of a small rod inserted in a nut at the end of the spring case. The diaphragm is very strong and will hold several times the pressure required. The working of this regulator is very simple. The water enters through the inlet coupling, 45, and passes through the chamber, 68, into the low pressure side of the regulator, the valve, 43, being held open by the tension of the spring, 53. When the low pressure has attained the desired limit, which is also felt in the diaphragm chamber through the hole which communicates with the chamber, 68, it forces down the diaphragm and seats the valve, 43. When the pressure again drops in the system, the diaphragm is forced up by the spring, 53, and the valve, 43, again opens.
An automatic throttle valve for a boiler feed pump is shown perspective and outline in Figs. [636] and [637]; this is a governor for the pump, controlled by the relative pressures of steam and water. It is known as Mullin’s automatic controller and is made at Seattle, Wash., and has the following features: