dual safety valve free sample

Besides the P/T value of the sleeve the limitations of the valve bodies also have to be considered. Please refer to the EN 12516-1 resp. ASME B16.34 in order to choose a proper pressure rating (PN/class). The shown values refer to austenitic stainless steel 1.4408 (A351 Gr. CF8M).

Besides the P/T value of the sleeve the limitations of the valve bodies also have to be considered. Please refer to the EN 12516-1 resp. ASME B16.34 in order to choose a proper pressure rating (PN/class). The shown values refer to austenitic stainless steel 1.4408 (A351 Gr. CF8M).

The primary purpose of a safety valve is to protect life, property and the environment. Safety valves are designed to open and release excess pressure from vessels or equipment and then close again.

The function of safety valves differs depending on the load or main type of the valve. The main types of safety valves are spring-loaded, weight-loaded and controlled safety valves.

Regardless of the type or load, safety valves are set to a specific set pressure at which the medium is discharged in a controlled manner, thus preventing overpressure of the equipment. In dependence of several parameters such as the contained medium, the set pressure is individual for each safety application.

Critical-application safety valves are functionally redundant, self-monitoring, and return to a safe position. It is easy to say that “Safety is everyone’s goal,” but what is really meant by that? Sound workplace safety practices can reduce the risk of injury to not only machine operators but to other people such as maintenance technicians; it can also reduce the risk that there is accidently damage to machinery and other company assets, or harm to the environment. Common industry standards acknowledge that there is no such thing as zero risk, while nonetheless providing guidance to machine builders and operators regarding how to take steps to minimize risks. This is commonly referred to as a machine safeguarding. Here’s a snapshot look at some key factors:

Alternative methods of controls offer two-time saving advantages. First, it uses a single lock-point (a remote, low-voltage system) that simplifies and speeds lockout, and enhances safety by avoiding the chance of a point being missed. The operator need not travel all around the machine to access various points to lockout or unlock operations. These systems place electrical lockout switches, connected to the control system, at locations that require machine access, and incorporate appropriate safety valves for pneumatic and hydraulic lockout.

The standard is also useful for tasks that are not routine, repetitive, or integral to production, but require power for, say, troubleshooting a control circuit. The new standard recognizes that there is no such thing as zero risk, and that some risk is present in order to perform certain tasks. In this case, the standard requires that the control system and valve controlling the non-isolated energy be control-reliable, Category-3 or -4.

There is no such thing as “zero risk”. Therefore, the standards require that you assess all possible risks, and determine what possible ways can be accomplished for most-effectively reducing those risks. The best approach to risk assessment is as a team. One big change ANSI B11.TR3-2000 brought about is that both the machine manufacturer and user are responsible for performing the assessment for new and rebuilt machines. In the past, machine safety was considered the user’s responsibility. Perhaps the most difficult part is defining the subjective words for the assessment. There are no precise answers, and even the standards differ. Users need to develop their own risk assessment program.

Many companies hold that there are two degrees of injury: minor and major. Minor injuries can be treated with a first aid kit, and anything requiring more extensive care is considered a major injury for risk assessment purposes. When a company uses a risk matrix that leans toward the “better-to-be-safe” side, the first question is, of course, “Will it entail additional expense to eliminate a rare possibility?” But to error on the high side forces the assessment team to look more carefully at each hazard. Often, safety can pay back in machine up time, reduced employee absenteeism, saving the time and cost to investigate an accident, insurance savings, and other hidden costs involved with accidents. Safety is part of a company’s loss-prevention program.

Avoiding using the wrong category valve should be the primary concern when performing a risk assessment. For example, a circuit with a single valve that suffers a broken spring or a sticky spool would have a different fault result than a similar circuit employing a double valve experiencing a broken spring or sticky valve. ANSI B11.TR3-2000 sets the recommended minimum level of control integrity as follows.Highest degree of risk reduction - Control systems having redundancy with continuous self-checking to ensure continuous performance.

Ross Controls Offers and expanded technical reference book "Fluid Power Safety for Machine Guarding", and a course in Fluid Power Safety, "TOTAL MACHINE SAFETY".

ROSS valves for Safety-related applications are designed to meet many Global standards including the following: CSA, Australian AS, EN, ISO, OSHA, ANSI, & CE