Globe Valve Seal Structure Improvement Experiment

Globe valve has simple structure, the valve opened or truncated by the principle of rotation and the lifting, and to ensure that the valve sealing function. Since the special structure of movement principle, also contributed extremely negative consequences for the valve sealing force(both form vertical pressure, and friction between relative slip and the seal pair).
The sealing portion of the valve stem is moved to the valve tap. The purpose is to force the process, so that the valve on the sealing surface slip stay in a static state. This improvement can increase the seal life, due to increasing the seal between the valve flap and valve cover, such structure is more complex, cost is relatively low.

Forged Steel Ball Valve Application

Forged steel ball valve is the preferred valve of gas pipeline, gas pipeline forged steel ball valve is forged steel structure, especially for gas, natural gas, acid gas, water, oil and coal slurry and other media conditions, suitable for Class150 ~ Class1500, on pipeline various conditions of oil, chemical, fire station, play a role of cutting off and turning on the media. Become forged steel ball valve materials are also carefully choose.
Ball valve used fixed structure, floating seat, under a pressure can be achieved less torque, using a self-lubricating PTFE metal sleeve, and high-strength, high-quality finish to fit the stem, the coefficient of friction to a minimum.
Forged pipeline valve use a polymer material as seat seal, sealing seat used a spring-loaded, with excellent sealing performance in a wide range of temperature changes and pressure changes, ensure no bubbles leaking seal.

The Reason of Valve Sealing Surface Damage

Valve sealing surface means seal portion between the seat and closure member, there are two causes of sealing surface damage, they are natural damage and man-made damage. The reason of man-made damage is ill design, not refined manufacturing, improper selection, incorrect installation, bad use and inadequate maintenance. The reason of natural damage is worn under normal operating conditions, inevitable erosion of medium and other factors. In the closed process, will bruise and pinch sealing surface, the sealing surface produce local indentation.
Improper selection and poor manipulation caused damage, mainly suitable valve is not selected according to the conditions, such as use the check valve as a throttle valve, leading to the closure pressure is too large, the sealing surface is eroded.
Installation errors and inadequate maintenance will lead to the sealing surface is not working properly, which can damage the sealing surface. 

Soft Sealing Gate Valve Advantages

1.The gate valve used flat-bottomed base, the fluid flows is unimpeded, debris and silt are difficult to precipitate in the base, not easy to cause pipe blockage.
2.The overall valve body is wrapped by plastic, size is reasonable and precise, ductile iron make valve body strong durable, not due to external impact or collision damage fracture, safe and durable.
3.The valve blotted out the environmental quality resin, corrosion resistant, safe and nontoxic. And can provide health drink.
4.Use the "o" seal technology, effectively reduce friction, without having to constantly replace the seals.
5.Valve body has light weight, easy to install, easy to maintain.

In addition, soft-sealing valve has some technical advantages. Conventional soft sealing gate valve can not be used if sealing surface will be found slightly distorted. the overall valve scrapped, this valve can avoid this phenomenon, the sealing surface has wear resistance, corrosion resistance, the average life is than six times than the general valve.

What Is The Difference Between Ball And Butterfly Valve?

The biggest difference between the ball valve and butterfly valve is opening and closing part. Butterfly valve opening and closing member is a plate, and the ball valve is a ball.
Butterfly structure principle is particularly suitable for production of large diameter, butterfly plate of butterfly valve installed in the pipe diameter direction. Ball valve are usually suitable for not particles of impurities liquid, the loss of fluid pressure is small, ball valve has good sealing performance.
Characteristics of butterfly valves is open and close fast, simple structure, low cost, but the rigor and bearing capacityis not good. Ball valve is difficult to achieve large-caliber by volume and resistance limits. Ball valve seal is a long-term squeeze on the sphere of the valve seat, ball valve sealing usually use flexible material, it is difficult to use in high temperature and pressure pipe. Butterfly valve seal is a rubber as an intermediary, they are large difference in ball valve, gate valve metal seal performance. Opening and closing process of ball valve can operate by the force of both ends of the valve seat, the butterfly valve opening and closing is achieved to overcome the deformation of rubber, greater torque.

Extend Seal Life of Globe Valve

Globe valve has simple structure, through the principle of the stem rotation and up and down, the valve opened or truncated, and to ensure that the valve seal and the sealing function. Since the special structure of movement principle, also contributed the valve sealing force extremely negative consequences.
Practice has proved that the valve seal will be poor due to the abrasion between the sealing. To solve these topics, we can improve the structure and material of the valve seal.
1.Place the seal area move to the valve, which can make the seal life long, but add one seal between valve cover and valve flap make the structure more complex, and cost is higher.
2.Change the sealing material. Surfacing good anti-abrasion performance carbide on the stem seal cone, this method has achieved good results, of course, the alloy cost is high slightly.

Common Failures of Butterfly Valve

The rubber elastic body in butterfly valves is used continuously, it will produce tear, abrasion, aging, or even perforation shedding phenomenon. The conventional thermal curing process is difficult to adapt to on-site repair needs, when repairing, use specialized equipment consume large amounts of heat and electricity, it is a waste of time but also a waste of energy.
Today phased polymer composite material alternative to the traditional method, products have excellent adhesion and excellent abrasion resistance, tear resistance, ensure that meet or exceed the repair cycle of new components, greatly reducing downtime.