708 SERIES FLOW CONTROL VALVE

Fractional Flow Control Valve for Precision Control

The Mark 708 series was developed by Jordan Valve (a division of Richards Industrials) to provide the most accurate control available for fractional flow services: whether for pilot plant installations, test stands, R&D test facilities, or for specialised processes such as dosing, injection and venting applications.

With Cv's ranging from 0.00001 to 4.0 available in 1/4" through 1" lines sizes (0.000009 to 3.4 Kv in sizes DN8 through DN20), the Mark 708 offers design features that will provide enhanced performance to ensure precision control on your most critical micro-flow applications.

The Mark 708 Series is a complete line of pneumatic and electric control valves developed specifically for the unique properties and conditions encountered in fractional flow services. The 708 Series comes standard with the quick change option - for applications requiring frequent trim changes without disturbing the actuator setting.

Features & Benefits:

• Rolling diaphragm – the rolling diaphragm design ensures that the effective diaphragm area remains relatively constant, regardless of valve stem position. This increases accuracy of the actuator when positioning the valve by ensuring a linear response to input signal changes.
• Spring-loaded TFE/Chevron packing – the spring-loaded packing maintains a proper compression, while minimising excessive friction. This alleviates the need for most field adjusting. The TFE packing is suitable for temperatures to 450°F (232°C), while braided or Graphite/Grafoil may be used for higher temperature requirements.
• Bolted body/bonnet connection – the bolting provides solid construction and secure connection. This bolting adds ease to maintenance, as bonnet/actuator assembly may be removed with the valve body in-line.
• Guided trim – extended orifice and plug guiding are standard and offers improved shutoff and accuracy equivalent to heavy duty trim option of competitors (not applicable to cv's below 0.05).
• Quick change trim – the secondary stem connection eliminates stroke adjustment when changing trim facilitating faster, easier trim changes (not applicable to cv's below 0.05).

Technical Specifications:

• Seat Type: Globe – Class IV or VI
• Sizes: 1/4? – 3/4? (DN8 – DN20)
• End Connections: Threaded, Socket Weld, Integral Tube, Welded Flange
• Body Materials: Carbon Steel, Stainless Steel, Hastelloy C, Monel, Alloy 20, others
• Cv (Kv): 0.00001 to 4.0 (0.000009 to 3.4)
• Ranges: 3-15 or 6-30 psi; split ranges are available with optional positioner

Applications & Industries:

• Pilot plant installations
• Test stands
• R&D facilities
• Processing plants
• Specialised processing plants (dosing, injection and venting)

LowFlow control valves and regulators are often used in OEM, laboratory or pilot plant applications for critical control of gases, liquids or steam. Installations such as these frequently require valve trim changes and a multitude of CVs in order to meet varying flow requirements for a given application. For a brief overview of the LowFlow product range, please click here to download our short catalogue.

For a brief overview/introduction to the Mark 708 series, please watch our video below:

• Hydrogen Products Mindmap