Injection Pressure Operated
Gas Lift Valve
N Series Valves utilize a nitrogen charged dome and bellow configuration designed for either continuous
or intermittent flow applications. They are especially suitable for use as unloading and operating valves in areas
where high gas lift pressures are available. Since the charge pressure above the bellows is affected by temperature,
it is important that the operating temperatures at the valve be known. These valve are available in both wirelineretrievable
and conventional installations.
Vibration protected, 3-ply monel bellow are designed to withstand hydrostatic pressure up to 5000 psi.
Nitrogen dome charge, acting on the O.D. of the bellow, permits bellows to expand uniformly without stacking, thus
prolonging bellow's life.
The multiple port size availability, make this valve series appropriate for a wide range of operating conditions.
Reversible seat available in several different materials.
The dome nitrogen charge applied to the external area of the bellows provides the downward force, holding the valve
on its seat. This dome pressure is preset at the reference temperature and corrected to operating temperature. The
opening forces on the valve are the casing pressure acting on the internal area of the bellows (less the area of the
seat) and the tubing pressure acting on the seat area. When the combined casing and tubing pressures are sufficient,
the valve opens. Once the valve is open, it remains open until the casing pressure is reduced to the predetermined
closing pressure. The spread (the difference between opening and closing casing pressure) is controlled by the
tubing sensitivity of the valve. The larger the seat port area, the more tubing sensitive the valve is.