Valves are dutiful servants serving diligently in critical sectors of the society. They are playing pivotal roles in the energy, agriculture and social sectors helping to make essential services no one can ignore their respective industry. Think of waterworks, oil and gas industry, and immigration available. When you are marveling at the wonder of valves in your industry, valves are doing even more in other sectors.
Growing demands for valves in strategic areas of economic and social sphere need more critical assessment of the quality of valves produced for various needs. Using low or inferior quality valves will no doubt end up spending more resources KP-LOK tubing valves and fittings including time and money on needless repairs than you’d like to. This could endanger your plant, equipment, and personnel, leaving them vulnerable to avoidable risk.
If you work in an industry surrounded by pipes and valves you probably need to consider the critical areas of service that equipment needs to render. Where there are many valve applications and service environments deemed critical by end users, governmental agencies, and standards development organizations, it is vital to ensure the right quality valves are deployed.
Critical service valves are expected to perform under extreme conditions. However, defining critical service applications is a difficult task, especially for isolation-type valves. To avert impending crises, informed businesses take to custom design valves for essential applications of service for Petrochemical, Refining, Chemical, Power Generation, Pulp & Paper, Oil & Gas, and Autoclave/Slurry Transport industries.
However, more clarity and agreement are necessary for the field of control valves. For instance, the following are situations deemed critical service applications by some control valve manufacturers:
- Where the flowing media may become harmful to people or the environment
- The potential for cavitations exists (water service).
- There is a high vibration or noise (steam service).
- A tight shutoff is required (ANSI/FCI 70.2, class V or VI).
- The valves are for flashing service.
- High pressures exist (ANSI class 300 and above).
- There are pressure drops of over 650 psi.
A wealth of industry standards is available to set specifications and thresholds for valves in various applications. E.g., API Standard 527 sets the maximum acceptable leakage rates for pressure relief valves. A lot of common process applications are deemed critical because of the fluids involved. On top of the list are valves in nuclear applications. Some popular services are:
- Nuclear Oxygen
- Hydrogen Highly corrosive
- Hydrogen Sulfide Emergency shutdown
- Chlorine Flammable fluids
Critical service valve design
Soft-seated ball valves debuted in the early 1960s. They are perfect choices for zero leakage. But, the soft elastomers used for sealing correctly also narrow their highest service temperature. Also, soft-seated valve closure members get damaged easily. In the efforts to mitigate the shortcomings, the metal-seated ball valve was developed in the late 1960s.
Another critical service valve design is the internally or externally refractory-lined slide gate valve used in flue gas or catalyst service. These valves usually operate at low pressures but temperatures up to 1400°F (760°C). Extremely fine closure adjustment and regulation are required, and these valves often employ exotic actuation systems to precisely adjust the flow rate.