高压铸的安全阀

Our forgedgate valves are designed as double-plates gate valves or double-plates parallel slides valves and are manufactured for suiting all pressure and temperature ranges. They can be in operation in large numbers for over 40 years both at home and abroad. The pressurised parts consist of forgings which are welded to the body using only one circumferential weld seam. The sizes and nominal diameters of our gate valve are given in the tables of dimensions. Our many years experience is a guarantee of a High level of technical development and operationally safe design. The body is forged in the direction of flow to form a middle section. The bonnet section is made of forged tubing and is welded to middle section. A single circumferential weld seam enables the weld to be exactly tested by X - rays, ultrasonics or other method. This high quality ensures that the body has adequate strenght. The valve is sealed by means of a self- sealing cover. Pressed graphite packings are used to increase the effect of the seal. The yoke piece on top of the valves is designed in all cases to take a direct drive. The spindle thrust is absorbed by heavy duty axial ball bearings and a radial ball bearing which are fitted in the upper part of the yoke. The spindle surface is ground to size, after which it is treated by superfinishing. This ensures the most favourable conditions for sealing and sliding in the region of the spindle packing. The sealing plates are suspended in a plate support so as to be self-aligning (see illustration). The pressure is transmitted by hardened ball segments and ball cups of large area which are inserted in the sealing discs. Absolutely tight sealing can be achieved by relatively Iow contact pressure. Our gate valves can therefore be opened and closed with little effort. It is possible to increase the spacing of the sealing plates (e. g. after grinding the sealing faces of the sealing rings) simply by inserting shims behind the ball Segments. The yoke piece on top of the valve is connected to the body by means of a two-part clamp which can easily be disconnected when dismantling or assembling. With the exception of the gland, there are no bolted connections under pressure. All machined metal parts are protected against corrosion before delivery. The external surface of the valve is primed.