A valve maker has come up with a compact design that provides high-precision sensitive flow regulation and integrates a leak-tight soft-seal shutoff control to give the functionality of a ball valve (shutoff) and a needle valve (metering) in a single package. Manufactured by Ham-Let, based in Sugar Land, Tex., the heart of the MBV Series valves is a patent-pending design that allows users to achieve various control configurations with a very fine and sensitive needle for flow regulation and calibration, while also including a diverting option for shutoff or full-flow position, without loading or damaging the sensitive regulation needle.
Ham-Let says its MBV Series facilitates a more efficient flow control scheme, eliminating the need for multiple shutoff and metering devices in series. As can be seen in the company-supplied diagram (below), previous to this industry users would mount a shutoff valve in series with a metering valve to control critical flows. This required additional tubing or piping segments as well as additional connection points, all of which are potential leak points. Ham-Let says its design eliminates these requirements and results in a more efficient flow control scheme with a smaller footprint, lower system weight, reduced internal dead volume and fewer potential leak points, which in turn reduces system weight.
The MBV Series is pressure-rated up to 2,000 psig (138 bar) and temperature-rated up to 300 deg F (138 deg C). Ham-Let makes different end-connections (male and female taper threaded, Let-Lok double ferrule compression, and HTC face seal) in sizes ranging from 1/16 in to 3/8 in. A choice of three precision stem tapers enables precise manual metering control as low as a Cv of 0.0001 with up to 11 handle turns and as high as a Cv of 0.15. Three different configurations cover this range: MBV-H, MBV-F and MBV-X. Ham-Let offers manual and optionally actuated diverting control.
The MBV’s metering accuracy is reportedly much more sensitive than conventional needle valves and for lower flow capacities. Flow calibration with conventional needle valves is relatively rough, since every change in handle/stem position creates a relatively large change in flow. In the MBV, its maker says flow is very moderate with relatively high resolution.
With the option of five O-ring materials, the MBV reportedly provides the temperature and chemical coverage for the oil and gas analyzing industries. A major application has been controlling flow inputs to industrial analyzers. Viton is the standard O-ring material, with NBR, EPDM, polychloroprene rubber (Neoprene) and perfluoroelastomer (Kalrez) as options.
Shell materials are made from marine-grade stainless steel (SS316), the seat is a polymer of tetrafluoroethylene and perfluorovinylether), the ball handle is molded from reinforced polyamide resin with SS316 as an option, while the metering handle is made from SS316 for the MBV-F and MBV-X models and anodized aluminum for the MBV-H, with an optional plastic Vernier scale handle.
Valve dimensions are approximately 100 mm height by approximately 56 mm width. Orifices measure from 0.8 mm to 3.3 mm depending on the model.
Recently, Ham-Let supplied the MBV Series to Vinci Technologies, a designer and manufacturer of pilot plants for the oil and gas industry. The company was pursuing a method of pressure control for its catalyst testing units to achieve high reliability but also cost effectively.
Vinci Technologies President Renaud Presberg explains: “In our catalyst testing unit the main challenge is to achieve the most cost-effective design and to assure reliable operation. With Ham-Let’s metering ball valves, we achieved both. The unique combination unit helped us to improve our design by reducing overall skid size and eliminating dead volume in the catalyst testing unit system. Additional benefits are reduced installation labor time and costs as well as more efficient operation for our customers.”
Meanwhile, chipmaker Intel adopted the MBV valve for sensitive helium leak detection from equipment used in the semiconductor fabrication process. Vacuum frames are used in the “sub-fab” of a semiconductor plant, with each vacuum frame possessing a gas stick whose purpose is to connect the frame to the helium leak detector mobile dispensing gun. Formerly, Intel used a gas stick construction that included a shutoff ball valve, a regulation valve and a quick connect. The problems were high cost (expensive valves), lack of user friendliness and the large trapped volume of helium.
The Ham-Let solution reportedly brought cost effectiveness through a single metering ball valve, elimination of the need for gas stick construction, more efficient control and real mobility with the dispensing gun in the sub-fab.