Shut-off valves are used in burner fuel supply lines on industrial boiler, heaters, thermal oxidisers, furnaces and other heating processes.
These valves are designed to shut-off fuel automatically and instantly on activation by the burner management system.
Few valves in the market are as closely linked to fuel shut-off application as Maxon valves which is how they are popularly known everywhere over the past 90 years.
Maxon valves come in two body designs - rising stem body with guillotine action for normally closed and normally open gas application and swinging gate body for fuel oil shut-off applications.
All Maxon valves feature a long lasting metal-to-metal seating design, which wears IN, not OUT. Armed with a powerful closing spring, the valve seat and disc continually clean themselves through frequent cycling, ensuring reliable sealing every time.
Every Maxon valve is operationally tested and must meet to the requirements of Flow Control Institute (FCI) 70-2-1998 (formerly ANSI B16.104) Class VI Seat Leakage standard before it leaves the plant.
Class VI seat leakage standard is the chosen industry standard for allowable seat leakage for fuel shut-off valve application.
Many valve manufacturers like quarter-turn ball valves provide soft seat options for compliance to this standard. Maxon valve is an exception with its unique and proven metal-to-metal seating and valve body design.
In comparison, soft-seated valves may be affected by erosion and damage from debris, which over time become an unsafe condition. Frequent repair or replacement will be required which will result in lost process downtime. Fuel shut-off valves are recommended to be leak tested on a regular basis. Choosing a reliable fuel shut-off valve is important for safe operation.
Maxon valves are available with electro-mechanical or air actuators with different voltage options (AC or DC) depending on the plant requirements. Various valve body material and trim options are available for compatibility in handling different types of fuel gases and fuel oils. All Maxon valves have visual position identification. Optional proof-of-position switches are also available. The valve top assembly enclosure meets to NEMA 1, 3, 3S, 4 and 12. NEMA 4X option is also available.
The family of Maxon valves suitable for hazardous locations will include:
• The electro-mechanical “NI” valve series have FM agency approval for use in hazardous locations: Class I Division 2. Available for fuel gas and oil.
• The air actuated ACTIONAIR series of gas and oil shut-off valves with FM approval for Class I Division 1 and Class I Division 2 hazardous locations
• The new compact design air actuated Series 8000 range of gas shut-off and vent valves have FM approval for use in hazardous locations, intrinsically Safe for Class I Division 1 and Non-Incendive for Class I Division 2
Maxon valves agency certifications are truly earned and deserving. Every valve component is built and assembled at the plant before being functionally tested as a complete Maxon valve. This is exactly why Maxon valve has only one serial number on its nameplate. The manufacturing and testing record of each Maxon valve can be traced back through its own serial number. Some competitive manufacturers build valves by packaging with code complying or type-tested third party actuators in order to obtain certification.
For plant operators using or considering the IEC 61511 process for their facility, there is good news.
Maxon “NI” and series 8,000 valves are now certified to IEC 61508. Maxon can offer FMEDA reports with full certifications under IEC 61508 as SIL 3 capable. SIL (Safety Integrity Level) is a combined measure of the durability and safety of a component or system.
SIL rating is created by examining the failure modes and failure probabilities for a device.
FMEDA (Failure Modes Effects Diagnostic Analysis) is a technical examination of a device to determine by what means the device is likely to fail wherein each means of failure is also assigned a statistical probability. It may be used to establish a product usable life cycle. Maxon is leading the competition in providing better quality, reliability and assured safety.
Performance, durability and reliability are the reasons why Maxon shut-off valves are the right valves on any burner fuel supply system.
It is a reputation that has earned worldwide trust and respect by heating equipment OEMs’ and plant operators.
