Showing posts with label severe service. Show all posts
Showing posts with label severe service. Show all posts

Sunday, December 9, 2018

What Are Trunnion Mount Ball Valves?

Trunnion ball valve design. Trunnions highlighted.
Ball valves are well understood in process control and industrial piping systems. Their simple 1/4 turn operation, compact form factor, bidirectional sealing, and tight shutoff make them a very popular choice for a wide range of applications.

Although there are many varieties of seat designs, body styles, and flow patterns, ball valves can be separated in to two main groups, distinguished by a primary design element - the mounting method of the valve ball.

The two groups are:
  • Floating ball
  • Trunnion mounted ball
Floating ball valves use the body and valve seats to position and hold the ball in the media flow path, allowing the flow force to lodge the "floating" ball firmly against the downstream seat. In this style, the ball is not mechanically held in place, thus the term "floating". Floating ball valves are, in general, limited to applications with smaller sizes and lower pressure ranges because, at some point, the fluid pressure on the ball may exceed the seat and trim's ability to hold the ball properly in place.

Trunnion mount valves, on the other hand, employ a "trunnion" in their design. A trunnion is a pin, or a pivot, forming one of a pair on which ball is mechanically connected and supported. The valve shaft and the trunnion connect at the top and bottom of the valve and create the vertical axis of rotation for the ball. The trunnion also prevents the ball from moving or shifting with changing pressures.

Due to their structural integrity, trunnion mount ball valves are generally well suited for all pressure ranges and valve sizes. Their design is used by many manufacturers for severe service. They provide excellent sealing properties over an extensive range of temperatures and pressures. Trunnion mount valves are available in both full and reduced bore designs with a wide range of materials, sizes, and pressure classes offered. The vast range of sizes, styles, pressure classes, and materials together with conformance to ANSI, API, and NACE specifications make these valves suitable for virtually all industrial, petrochemical, refinery, and oil and gas services. Finally, there may be an advantage to actuate trunnion ball valves due to lower torque requirements compared to similar floating ball valves whose torque increases with increasing flow pressure.

For more information on floating ball or trunnion mount ball valves, contact Piping Specialties, Inc. at 800-223-1468 or visit https://psi-team.com.

Thursday, July 12, 2018

MOGAS Severe Service Ball Valve "Mate Lap" Seal Demonstration

The video below demonstrates the effectiveness of the MOGAS "Mate Lap" seal provided on MOGAS severe service ball valves.

MOGAS valves have outperformed others worldwide in some of the most severe service conditions, including: Extreme temperatures; High pressures; Abrasive particulates; Acidic products; Heavy solids build-up; Critical plant safety; Large pressure differentials; Velocity control; Noise control.

Wednesday, January 31, 2018

Conval Clampseal Valve Disassembly Instructions

Conval Clampseal® Valves are much easier to renew than anything else on the market. This video is one of a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468

Thursday, October 12, 2017

Mogas FlexStream: Rotary Control Technology for Severe Service Applications

Process plants have increased throughput causing operating pressures and flow rates to increase as well. Advanced production techniques demand better equipment and valve performance to handle these severe conditions. FlexStream rotary control technology is designed specifically for severe service conditions, to provide superior velocity control, variable characterization, exceptionally high rangeability, and precision modulation.

Mogas FlexStream
1) Diffusion element splits and aligns the flow.
2) The control element reduces the flow velocity.
Within a compact replaceable trim design, located downstream with a seat, FlexStream technology employs flow paths of different configurations to control flow and pressure drop. First the diffusion element splits and aligns the flow, then the control element reduces the flow velocity through a variable arrangement of torturous flow path. This allows precise pressure let down, and velocity control custom tailored to process conditions. These torturous flow paths consist of a series of right angle turns. Pressure is reduced by directing fluid flow through these right angles, which control kinetic energy and velocity. Pressure drop at each stage is evenly distributed, while the torturous path expands at each right angle to ensure velocities will not be increased. The larger the pressure drop, the more turns are required to control velocity.

For applications requiring high rangeability, ideal flow control is available by varying the combination of control area and open area, within the trim. The control area determines the amount of bore filled with multi-stage paths, and is used for higher pressure drop lower flow conditions. The open area determines the amount of unrestricted flow, and is used for lower pressure, drop higher flow conditions. This custom fill characterization can vary from 30 to 100 percent, depending on flow conditions, pressure drop, noise level, and outlet velocity required. Precise process and velocity control are achieved at every stage of valve opening, with exceptionally high rangeability in a single control valve.

For gas and steam applications, extreme noise and vibration are reduced or eliminated. The patented FlexStream technology expands upon the strengths of Mogas quarter turn ball valves to offer application-specific trim engineered for high delta-P applications, replaceable control element design, greater Cv per inch compared to the competition, and a smaller dimensional envelope in a traditional control valve.