Working Principle:
Flange globe valve is a kind of forced sealing valve, relying on the pressure of the valve bar, so that the sealing surface of the valve flap and the sealing surface of the valve seat are closely adhered to, so as to prevent the flow of the medium. Because the flow direction of the globe valve is always used from top to bottom, then under the action of medium pressure, the force to close the valve is small, the force to open the valve is large, the diameter of the valve stem can be reduced accordingly. At the same time under the action of the medium, this form of valve sealing performance is also better.
Cast Steel Flange Globe Valve Structure Features：
1. The valve body bonnet connection: PN10-PN100 with bolted bonnet; PN160 and above with self-pressurized sealed bonnet.
2. The opening and closing parts (valve flap) design: usually a flat sealing valve flap, according to customer requirements and the actual working conditions require the use of taper sealing valve flap, the sealing surface can be according to the user's requirements of the gold surfacing materials or inlaid non-metallic materials.
3. The bonnet in the gasket form: PN10 ~ PN40 globe valve with stainless steel graphite composite gaskets; PN63 ~ PN100 globe valve with stainless steel graphite wound gaskets; PN160 self-sealing globe valve with self-pressure sealing metal ring.
4. Packing seal: packing part is usually filled with flexible graphite material, according to the demand for PTFE or composite packing material.
5. Operation form: handwheel or worm gear drive is usually adopted, and chain wheel drive, pneumatic and electric drive can be adopted according to the needs of users.
6. Stem nut: Normally, the stem nut is made of stainless steel or copper alloy. According to user requirements can be used high nickel cast iron and other materials, for large caliber globe valve: stem nut and stem between the design of rolling bearings, can reduce the opening torque of the globe valve so that the valve can be light switch.
Advantages & Disadvantages:
Advantages:
1. Opening and closing the valve flap stroke is small, so the height of the globe valve is smaller than the gate valve.
2. Open and close the process of friction between the sealing surface is small, not easy to wear and abrasion, and therefore long service life.
3. Flange globe valve structure is relatively simple, manufacturing and maintenance are more convenient.
4. The valve increases a top seal, when the valve is open, with the packing together with two layers of sealing effect, sealing performance is better, and the packing has a certain protective effect.
Disadvantages:
1. Because the valve body media channel is more zigzag, so the fluid resistance and power consumption.
2. The cut-off valve medium can only flow in a single direction from top to bottom, can not change the direction of flow, so it is not suitable for particles, viscosity, easy to coking medium, otherwise it is easy to cause clogging.
