The Solution – HY-GRADE Valves
CGIS has been successful in providing a check valve into the first stage of separation for a CSG-LNG operation, that gives repetitive zero-leakage shut off while significantly outlasting the previously installed duo check valve
HY-GRADE is a US-made check valve using only US or Western European raw forged or wrought materials for all pressure containing components.
The HY-GRADE Valve advantages over the current duo check valves are:
The ability to be sized correctly on an individual valve basis to prevent disc chatter.
In single phase flow or multi-phase applications where density is inconsistent, the inlet of a HY-GRADE check valve can be sized so that it provides enough flow velocity to keep the disc in the fully open position with no chatter. Due to the replacement seat insert, the same valve body can be used as the pressure and flow in the line changes over the course of the well life, the orifice size can be changed in the field for a reduced cost in comparison to a new valve.
Full bore retainer-less body- zero leaks to the atmosphere while giving the highest Cv (see figure. 2).
When comparing the fully machined HY-GRADE valves to a standard duo check valve, the duo check valve has a shaft and seat retainer positioned through the bore of the valve which reduces pipeline Cv and is subject to the abrasive/corrosive nature of the media. The shaft and discs are held in place by nuts, bolts and retainers external from the valve body making them a potential leak path. As can be seen from figure 2, the HY-GRADE valve design eliminates all those failure modes whilst producing a high Cv.