The Technology within Gate Valves – Anix USA

knife-edged valve is an interrupter valve, meaning that it is used to initiate and interrupt flow in the pipe. Gate valves and knife valves are designed to minimize the pressure difference between valves when they are in their full opening position, and stop fluid flowing through them entirely.

Because vibration causes wear on the seats and pucks, resulting in leakage, gates should be used in only fully opened or fully closed positions. Flexible shims prevent binding of the gate inside the valve when valve is closed.
The heart of the gate valve is the closing member, which comes in two designs, a wedge-shaped one, or a parallel one. The rectangular closure element has a circular aperture that is the same size as the gate valves entire area of the flow path; when the element is dropped, the aperture is exposed to the flow. Gate valves are distinguished from ball, plug, and butterfly valves by having a closure element, called the disk, gate, or obturator, rising up from the flowway at the base of the spindle or spool, into the top of the valve, called the hood, through several turns of the spindle or spool.

When closed, the plate gate blocks media flow, while downward pressure on one plate (the stem) and upward pressure on another plate (the steps of the valve body) permit mechanical outward expansion to ensure a proper sealing. To keep the tight seal, when opened or closed, valve stems, seats, and gates should always be protected from the elements. The protected seat-face design of the Double Expanding Pivot Gate Valves and Slab Gate Valves prevents degradation of the seat faces caused by process fluid debris, making them ideal for fluid services.
The efficient sealing makes gate valves perfect for applications such as isolated valves in power plants, blocking valves in process systems, and high-temperature valves in oil refineries. Our proprietary Single Load Spring (SLS) design of the shaft seal used on the Saf-T-Seal plate gates and the WKM Pow-R-Seal double expansion gates offers excellent leakage protection with an auto-adjusting sealing design that simplifies maintenance. The spring-loaded PTF sealed insert used in Anson gates is designed specifically for rough use, providing a durable, long-lasting sealing performance.

Our smaller, non-rise-stemmed, 2-in-4-inch versions of API 6A expandable gate valves with the Pow-R-Seal are typically used in wellhead header systems for their robust mechanical sealing and high-pressure capabilities. High-performance butterfly and metal-sealed ball valves are beginning to find increased application in refinery applications, though they typically have higher overall costs of ownership compared with the gate valve. Because its latest products are integral, gate valves are extremely simple to operate--basically plug-and-play--which lowers the risks of assembly as well as increases reliability. The knife-edged gate valve is mostly used in fluid-based applications and configurations, particularly when dense materials are involved.

Use ensures the seal of the valve is not compromised by a material being trapped between its components. Widely used in critical industrial applications, one of these specialty fixtures is one of the more crucial components of the systems chosen. Gate valves typically provide a first-point shutdown capability to nearly all drill rigs, in various applications and uses.
When used for flow regulation, the relatively high velocity of the flow in a portion-opening situation results in wear on the gate and seats, and the potential for vibration in the gate reduces the life of a gate valve. Using a partially opened gate valve to throttle or regulate flow may cause either puckering or seat-ring wear of the housing, as seat surfaces are struck by each other in a partly opened, turbulently-induced flow environment.

The design allows for bending of the gate, when the valve seats are compressed with the heat of steam from the system. This line of gates offers several options for the user depending on their particular application, including the ability to obtain a positive seal in pressures ranging from zero to 15000 PSI at wellbore/flowline locations.