How to ensure the sealing performance of plug valve is leak-proof?

As a valve salesperson with 8 years of experience, I am often asked by customers: "Can your plug valves achieve absolute sealing?" And Engineer Zhang from the technical department always smiles and says: "Sealing is like putting a protective mask on the pipeline. It needs to fit tightly and also have to withstand various environmental tests." Today, from both business and technical perspectives, we will take you to uncover the secrets of the sealing performance of plug valves.

Ⅰ. Design is the first line of defense for sealing

When we bid for a large petrochemical project, the client put forward very strict requirementa: the valves must be completely leak-proof. This must be ensured even under temperatura fluctuations ranging from -40℃ to 350℃. Our teams worked together and used advanced computer models to test many solutions. Eventually, they came up with the design: the valve components fits together like two cones at very precise angles. This resulted in a sealing effect far superior to the conventional design, achieve a more secure and reliable connection.

The elastic sealing design is better at handling complex working conditions. In a certain natural gas pipeline project in Southwest China, we customized a lip-shaped rubber sealing ring for the client. When installed, this sealing ring would generate a pre-compression of 3-5mm. Even if the pipeline was slightly shaken or underwent thermal expansion and contraction, the sealing surface maintained a contact pressure of over 0.2MPa. During a recent follow-up visit, the client's operation supervisor stated: "This valve has been in use for three years and has not leaked a single bubble."

Ⅱ. Material selection determines seal life

So, we need to choose the long latsing material to ensure the sealing performance of the plug valve. In one of us project in a marine project, we ues the Hastelloy C276 body, paint a tungsten carbide coating on the seal surface. This combination can provide a effective function, protecting the plug valve from damp and salty sea breeze, extending service life.

ZZJG Engineer Zhang is proud of this, saying "we use aser cladding on surface—got it up to HRC65. Even if some rough items flow through the valve, valve sealing surface will not be damaged easily.

For the high corrosive enviroment, like chemical plant dealing with concentrated hydrochloric acid, we design a special multi-layer sealing. This keep our plug valve work smoothly, continuously for 18 months at a high temperature of 120°C and 1.6MPa. This is much better than the usual level in the industry!

Ⅲ. Details in the manufacturing process

In ZZJG workshop, every working procedure have its secrets. On CNC grinder, we use mirror grinding technology, which can help to control the sealing surface roughness less than Ra0.2, equivalent to an area of 1 square centimeter witha flucuation of no more than 0.0002 mm. Engineer Wang, ZZJG quality inpestion supervior introduced, "Our helium mass spectrometers leak detector can detect extreme small leaks of 10^-9 Pa·m³ per second, 100 times more sensitive than ordinary methods."

In coal chemical project, the customer required the valves to withstand high temperature of 800℃. We optimize the inverted seal structure through finite elements analysis, add a expanded graphite sealing ring to the top of the valve stem, adopted a stepped clamping design.In actual operation, even after 100 thermal cycles, the valve stem still maintains zero leakage.

Ⅳ. Sealing guarantee throughout the entire life cycle

As a salesperson, I pay much attention to customer's experience about the plug valve. We carefully write down the details about every items, like installation environment, media information, etc. In our aftersale service, we found one of our customer, a food and beverage company's improper cleaning causing the sealing surface corrosion. We provide specialized cleaning agents and maintenance guidelines timely, which help the customer decrease 40% valve maintenance cost.

Technical department is still develope a smart sealing monitor system, which can monitor the tiny change deformation and temperature change by built-in pressure sensor and optical fiber probe. ZZJG Engineer Zhang told, this smart monitor system can give a 15-day advance warning of the risk of seal failure, just like we install a intelligent physical examination instrument on the valve.

Sealing performance is the key to ensure project safety. From design, manufacture to maintenance, every step must be cooperated by prepositional team. When I be asked "How long is the sealing life of your valves?", I can reply it confidently, "we provide not only the high-quality products, but also a full-process sealing solution." This is ZZJG VALVE commitment to our profession and customer.