Thursday, September 28, 2017

Breathing Air Purifiers

breathable air purifier system
A breathing air purifier unit processes
compressed air, making it suitable for respirators.
Image courtesy SPX Pneumatic Products
There are many instances throughout science and industry where tasks must be performed by human operators in environments without breathable air. In many of those cases, it is necessary to provide a positively pressurized enclosed space around the operator's face to isolate the breathing passages from potentially harmful vapors, dust, or pathogens in the work area.

Applications in the petrochemical industry, as well as asbestos abatement, paint and coatings, tank cleaning and more have specific jurisdictional requirements for the provision of breathing apparatus for worker protection. A compressed air source is processed as it passes through a purifier which imposes a six stage filtration process on the compressed air inlet prior to supplying the breathable air to safety hoods or masks.

  • Removal of solid and liquid particles or droplets greater than 1.0 micron.
  • Oil and liquid aerosol removal down to 0.1 micron.
  • Water vapor removal
  • Reduction of carbon monoxide level
  • Second particulate filtration stage to 1.0 micron
  • Activated carbon removes trace odors, oil vapor, and other components
Analyzing and monitoring the outlet air quality from the purifier unit is a good practice, to assure that target levels of oxygen, carbon monoxide, moisture, and carbon dioxide are maintained. OSHA and other jurisdictional bodies specify allowable levels for certain potentially harmful gases. The quality of the inlet air should be carefully assessed and protected during operation, since it is a primary determinant of the outlet air quality.

Share your process requirements with a pneumatic system specialist, combining your own knowledge and experience with their product application expertise to develop an effective solution.

Wednesday, September 20, 2017

Trunnion vs. Floating Ball Valves

trunnion mount ball valve for industrial pipeline use
Trunnion mount ball valves have upper and lower support
points for the ball.
Image courtesy International Standard Valve, Inc.
The design, construction, and function of a ball valve is generally well understood in the industrial fluid processing arena. Ball valves provide reliable quarter turn operation, compact form factor, and tight shutoff capability, making the ball valve a preferred choice for many applications. Some ball valves also provide shutoff of fluid flow in either direction. A primary valve trim design feature permits grouping of the many variants of industrial ball valves into two categories, distinguished solely by the way in which the ball is mounted in the body.

Floating ball valves use the seats and body to hold the ball in place within the fluid flow path, with the force of directional flow pushing the ball against the downstream seats to produce a tight shutoff seal. Many floating ball valves are capable of flow shutoff in either direction. The ball is rotated by a shaft connected at the top which extends through the pressure enclosure of the valve for connection to a handle or automated actuator. The floating nature of the ball limits the applicability of this design to smaller valve sizes and lower pressures. A some point, the fluid pressure exerted on the ball surface can exceed the ability of the seats to hold the ball effectively in place.

Trunnion mount ball valves employ the stem shaft and, you guessed it, a trunnion to rigidly position the ball within the body. The shaft and trunnion, connected to the top and bottom of the ball, establish a vertical axis of rotation for the ball and prevent it from shifting in response to flow pressure. The trunnion is a pin that protrudes from the bottom side of the ball. It sits within a bearing shape, generally cylindrical, in the base of the body.

Because of their structural design, trunnion mount ball valves are suitable for all pressure ranges and sizes.They are used by many manufacturers as a basis of design for their severe service ball valve offerings. A trunnion mount ball valve can also be advantageous for applications employing valve automation. Since the ball is not held in place by a tight fitting seal arrangement, operating torque tends to be lower for comparably sized trunnion mount valves, when compared to floating ball valves.

On page 3 of the brochure included below, the exploded view of a trunnion ball valve shows the location of the trunnion assembly.

Whatever your valve application challenge, share it with an industrial valve expert. Leverage your own process knowledge and experience with their product application expertise to develop an effective solution.


Thursday, September 14, 2017

Pressure Measurement Using Isolation Ring



The D81 Isolation Ring from Winters Instrument provides a solution for measuring system pressure in processes involving fluids with potential to clog or damage sensors and impulse lines. The isolation ring has a hollow elastomer that is located between two flanges. A fitting on the elastomer section allows for connection of a gauge or transmitter without disturbing the process fluid. Pressure in the piping system is mirrored by pressure within the hollow portion of the isolation ring, measured by the connected instrument. The instrument does not come in contact with the process fluid, nor are there any small diameter impulse lines to foul or clog. Applications in mining, water treatment, pulp and paper abound. Any challenging fluid is a good candidate for application consideration. Models are available up to 48" line size, with wafer, flanged, or threaded connections.

Share your fluid process measurement requirements with application specialists, combining your own knowledge and experience with their product application expertise to develop effective solutions.