Continuous and Point Level Control Selection Guide

Drexelbrook Continuous and Point Level Control
Drexelbrook Continuous and Point Level Control Products
Based on experience from of thousands of inquiries about level measurement, most questions boil down to "What is the best level measurement instrument for my application? That depends on quite a few application considerations, such as:
  • Will the measured media add coating to the probe?
  • Can the probe have contact with the media?
  • Are there explosion hazards?
  • What is the physical type of application, well, tank, open channel or floating roof tank?
This document can help deliver the perfect continuous level transmitter or level switches for your application.

Download a PDF version of the Drexelbrook Continuous and Point Level Control Selection Guide here, or view the embedded document below.

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

Considerations for Choosing Industrial Butterfly Valves

Butterfly Valves
High Performance Butterfly Valve
(Pratt)
Industrial process control valves are available in uncountable combinations of materials, types, and configurations. An initial step of the selection procedure for a valve application should be choosing the valve type, thus narrowing the selection field to a more manageable level. Valve "types" can generally be classified by the closing mechanism of the valve.

A butterfly valve has a disc that is positioned in the fluid flow path. In the most common form of butterfly valve, the disc rotates around a central axis, the stem, through a 90 degree arc from a position parallel to the flow direction (open) to perpendicular (closed). A variety of materials are used in the valve body construction, and it is common to line the valve with another material to provide special properties accommodating particular process media.

What attributes might make a butterfly valve a beneficial selection over another valve type?
Butterfly Valve
Resilient Seated Butterfly Valve
(Pratt)
  • The closure arrangement allows for a comparatively small size and weight. This can reduce the cost, space, and support requirements for the valve assembly.
  • Generally low torque requirements for valve operation allow for manual operation, or automation with an array of electric, pneumatic, or hydraulic actuators.
  • Low pressure drop associated with the closure mechanism. The disc in the flow path is generally thin. In the fully open position, the disc presents its narrow edge to the direction of flow.
  • Quarter turn operation allows for fast valve operation.
  • Some throttling capability is provided at partially open positions.
  • Small parts count, low maintenance requirements.
What may be some reasons to consider alternate valve types?
  • Butterfly valve throttling capability is generally limited to low pressure drop applications.
  • Cavitation can be a concern.
  • Some sources mention the possibility of choked flow as a concern under certain conditions.
Butterfly valves, like other valve types, have applications where they outperform. Careful consideration and consultation with a valve expert is a first step toward making a good selection. Combine your process know-how with the product application expertise of a professional sales engineer to produce the best solutions to your process control challenges.

For more information regarding an type of industrial valve, contact Piping Specialties, Inc. by visiting https://psi-team or by calling 800-223-1468.

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.

Happy Fourth of July from Piping Specialties

"America is much more than a geographical fact. It is a political and moral fact — the first community in which men set out in principle to institutionalize freedom, responsible government, and human equality." 

Adlai Stevenson


Best Practices Document for the K-Patents PR-23-SD Safe-Drive™ Process Refractometer

K-Patents PR-23-SD Safe-Drive
This document is intended for individuals installing, commissioning, operating, and/ or servicing the Safe-DriveTM Process Refractometer PR-23-SD, generation 2.1 model. The purpose of this document is to provide a quick guide for the abovementioned tasks in the form of K-Patents recommended best practices.

This document is intended for PR-23-SD applications that have a steam wash system (typical application for black liquor) and applications that have high pressure water wash system (typical application for green liquor).

NOTE: These instructions are for quick reference only. For more thorough guidance, please refer to the K-Patents user manual and documentation that came with your equipment.

Review the embedded document below, or download a PDF version of Safe-Drive™ Process Refractometer PR-23-SD Generation 2.1 Best Practices here.

Operating Principles and Application of Vortex Flowmeters

Animation of vortices*
To an untrained ear, the term "vortex flowmeter" may conjure futuristic, potentially Star Wars inspired images of a hugely advanced machine meant for opening channels in warp-space. In reality, vortex flowmeters are application specific, industrial grade instruments designed to measure an important element of a fluid process control operation: flow rate.

Vortex flowmeters operate based on a scientific principle called the von Karman effect, which generally states that a fluid flow will alternately shed vortices when passing by a solid body. "Vortices" is the plural form of vortex, which is best described as a whirling mass, notably one in which suction forces operate, such as a whirlpool. Detecting the presence of the vortices and determining the frequency of their occurrence is used to provide an indication of fluid velocity. The velocity value can be combined with temperature, pressure, or density information to develop a mass flow calculation. Vortex flowmeters exhibit high reliability, with no moving parts, serving as a useful tool in the measurement of liquid, gas, and steam flow.

Photograph of vortices **
While different fluids present unique challenges when applying flowmeters, steam is considered one of the more difficult to measure due to its pressure, temperature, and potential mixture of liquid and vapor in the same line. Multiple types of steam, including wet steam, saturated steam, and superheated steam, are utilized in process plants and commercial installations, and are often related to power or heat transfer. Several of the currently available flow measurement technologies are not well suited for steam flow applications, leaving vortex flowmeters as something of a keystone in steam flow measurement.

Rangeability, defined as a ratio of maximum to minimum flow, is an important consideration for any measurement instrument, indicating its ability to measure over a range of conditions. Vortex flowmeter instruments generally exhibit wide rangeability, one of the positive aspects of the technology and vortex based instruments.

The advantages of the vortex flowmeter, in addition to the aforementioned rangeability and steam-specific implementation, include available accuracy of 1%, a linear output, and a lack of moving parts. It is necessary for the pipe containing the measured fluid to be completely filled in order to obtain useful measurements.

Vortex flowmeter
(Azbil)
Applications where the technology may face hurdles include flows of slurries or high viscosity liquids. These can prove unsuitable for measurement by the vortex flowmeter because they may not exhibit a suitable degree of the von Karman effect to facilitate accurate measurement. Measurements can be adversely impacted by pulsating flow, where differences in pressure from the relationship between two or more compressors or pumps in a system results in irregular fluid flow.

When properly applied, the vortex flowmeter is a reliable and low maintenance tool for measuring fluid flow. Frequently, vortex flow velocity measurement will be incorporated with the measurement of temperature and pressure in an instrument referred to as a multivariable flowmeter, used to develop a complete measurement set for calculating mass flow.

Whatever your flow measurement challenges, share them with a flow instrument specialist, combining your process knowledge with their product and technology expertise to develop effective solutions.

* Animation of vortex creation credit Cesareo de La Rosa Siqueira via Wikipedia.
** Photograph of vortices credit J├╝rgen Wagner via Wikipedia.

Providing New England Industry with Process Instrumentation, Valves, and Unsurpassed Service for Over 40 Years

PSI operates under one single mission: To provide specialty valves, instruments, control systems and mechanical products to industrial users throughout the Northeast, and to do so by providing unsurpassed customer service.

Covering the states of Maine, Vermont, Massachusetts, New Hampshire, Rhode Island, and Connecticut through offices located in Portland, Maine and Danvers, Connecticut, PSI is well situated to provide quick delivery, on-site services, and engineering support all through New England.

Piping Specialties, Inc. provides industrial valves, including ball, butterfly, gate, globe, safety relief, and control vales; and mechanical specialties including, steam traps, condensate recovery systems, steam water heaters, site level gauges, jet pumps, expansion joints, and modular pipe seals.

PSI Controls provides automated industrial and commercial valve packages that include quarter-turn and linear valves, pneumatic and electric actuators, limit switches and valve communications; and process instrumentation & controls including level, pressure, temperature and flow  instrumentation.

PSI Services provides installation of valve automation systems, valve repair, instrument repair, instrument calibration, turnkey systems and field support services.