Key SIL (Safety Integrity Levels) Terms

Safety Integrity Levels

The global value of SIL (Safety Integrity Levels) to the process industries has increased significantly over the years. For many companies, SIL is still an elusive term sometimes misunderstood and implemented incorrectly. To fully understand SIL and its consequences, it is essential to comprehend the necessary words, acronyms, and phrases often used and how they relate to the pursuit of functional safety.  The following are some of the most commonly used:

Dangerous failure

Failure with the potential to bring the safety instrumented system into a dangerous or non‐functional state.

FMEDA

Failure Modes Effects and Diagnostic Analysis

HFT

Hardware Fault Tolerance, ability of a hardware to continue to perform a required function in the presence of faults or errors.

MTBF

Mean Time Between Failures

PFD

Probability of Failure on Demand, Probability of hazardous failures for a safety function on demand.

Safety Function

The ability of a system to carry out actions necessary to maintain a defined safe state for a process, equipment, or a plant.

Safety‐Related System

A safety‐related system performs the safety functions that are required to maintain a safe condition (for example, a flow meter, a burner, and a PLC).

SFF 

Safe Failure Fraction, percentage of failures that do not have the potential to put the safety‐related system in a hazardous state.

SIL

Safety Integrity Level, IEC 61508 defines four Safety Integrity Levels (SIL1 through SIL4). Each level corresponds to a level of probability for the failure of a safety function.

SIS 

Safety Instrumented System, implementation of one or more safety instrumented functions.


Piping Specialties / PSI Controls
800-223-1468

Terms and definitions courtesy of Kurz Instruments

The Operation of the Cash Valve B Series, Type E-55, Type PBE-1, Type PBE-2, and Type PBE-5

Cash Valve is a leading manufacturer of pressure regulating and back pressure valves offering products for steam, air/gas, liquid, and cryogenic applications. Products range in size from 1/8" - 2" for threaded NPT connections and up through 6 inches for flanged configurations. Temperatures range between cryogenic up through 800°F, and materials of construction are offered with iron, brass, bronze, carbon and stainless steel depending on your application.

For more information about Cash Valve, contact Piping Specialties, Inc. by calling 800-223-1468 or by visiting their web site at https://psi-team.com

A Free Technical Paper Explaining Refractive Index

Refractive Index

Refractive index measurement is a measurement of the speed of light in a medium. The speed of light (usually denoted by c) is 299 792 458 m/s in a vacuum. In other media, the speed of light is lower, and the refractive index (R.I.) of a medium is how much slower the light's speed is in the medium.

The detection of liquid concentrations by optical means is not new. The law of refraction was mathematically formulated first by Ibn Sahl in 984 but not known in Europe. Instead, its discovery misattribution goes to the Dutch astronomer and mathematician Willebrord Snellius (Snell), who rediscovered the law and published it in 1621. The first laboratory instrument to accurately measure liquids' refractive index was developed by Ernst Abbe in 1874.

This technical paper, courtesy of Vaisala K-Patents, is a technical explanation and understanding of the refractive index.

For more information about industrial refractometers, contact Piping Specialties / PSI Controls by calling 800-223-1468 or by visiting their web site at https://psi-team.com.


Valve Condition Monitoring

Valve Condition Monitoring

As corporations worldwide are increasingly concentrating on their bottom-line margins, there is an increased drive towards efficiency and productivity in industrial operations. Operators are also looking to respond to industry concerns about aging assets. All manufacturing activities are continually motivated to improve performance and productivity to boost profit margins and optimize bottom-line returns. This drive takes place in many industry sectors against a backdrop of increased health, safety, and environmental issues and the need to make changes to old assets that can sometimes run beyond their original design lifespan.

Reducing the number of unscheduled plant shutdowns is an essential way of fulfilling these targets. Unplanned shutdowns are mostly related to worn-out machinery and are attributable to exceeding process equipment's longevity in many instances. Operators may avoid expensive shutdowns and increase production uptime with a regular maintenance schedule and a condition monitoring solution that minimizes maintenance spending and improves plant safety. Asset tracking, asset management, and predictive maintenance solutions are, therefore, becoming increasingly common.

Valve condition monitoring's goal is to detect and prevent possible failures before causing unsafe conditions and unplanned downtimes.

Since valves are a critical component of any flow-based operation, valve efficiency is an essential factor to check when trying to avoid unplanned maintenance, or worse, shutdowns of plants and the resulting loss of batch output.

Although some operators already deploy condition monitoring on control valves and critical valves, many valves are often left unmonitored, particularly those used for on / off and shutdown applications. Although the technology for controlling these valves is available, operators are discouraged from such an investment because of the prohibitive hardware and installation cost. 

Although some valve manufacturers have touted various valve testing and monitoring systems, many proposed solutions can pose operational, financial, and/or technical implementation problems. This is because they are usually considerably more expensive than conventional methods or require new electrical systems and hardware to accommodate and enhance the monitoring software. Suppose automation is at the most basic level, such as that needed with on/off valves. In that case, the transformation is relatively low in value. The time and resources involved in implementing a useful monitoring solution can be challenging to justify. However, the consequence is that vast numbers of on/off valves are not supervised and pose a significant risk of valve failure.

By implementing this technology cost-effectively on all automatic valves, a plant will provide production efficiency and avoid unspecified delays and unsafe conditions. Valve Condition Monitoring is useful to all operating phases of the plant and thus provides the ability to increase all current and future installations' performance and safety. If you are considering updating your plant's valve monitoring strategy, contact a local expert who can guide you through all the ups and downs. The information they provide is truly invaluable. 

Piping Specialties / PSI Controls
800-223-1468 

A-T Controls Industrial Valve, Actuator and Controls Product Overview

A-T Controls in New England

A-T Controls is a global leader in the design, manufacturing, and sale of manual & automated process valves for all types of industries. A-T Controls is known for its extensive inventory and highly experienced staff that enable them to provide the customer solutions needed to fulfill most valve and actuator requirements while offering both a competitive price and the fastest turnaround in the industry.

A-T Controls products provide high-performance operation in virtually every industry, including Oil & Gas, Refining, Petrochemical, Chemical Processing, Pulp & Paper, Mining, Transportation, Food and Beverage, Pharmaceuticals, Marine, HVAC, Power, and more.

A-T Controls Products Include:

High Performance Butterfly Valves; Resilient Seated Butterfly Valves; Trunnion Mounted Ball Valves; Pig Valve Dual Valve; Isolation Valve Assemblies; Cryogenic Ball Valves; Lined Ball Valves; Tank Bottom Valves; Electric Actuators; Spring Return Electric Actuators; Fail Safe Electric Actuators; Heavy Duty Actuators; Pneumatic Scotch Yoke Actuators; Pneumatic Rack & Pinion Actuators; 180ยบ Pneumatic Actuators; Stainless Steel Pneumatic Actuators; Declutchable Gear Operators; Gear Operators; Limit Switches; Solenoids; Positioners.

DOWNLOAD THE A-T CONTROLS PRODUCT GUIDE

For more information, contact Piping Specialties, Inc / PSI Controls. Call them at 800-223-1468  of visit their website at https://psi-team.com.