Angle valve with hammerless grinding
In an angle valve, an externally threaded sleeve within the yoke surrounds the stem at an upper end of the stem. A yoke bushing fixed to the valve has internal threads matching with the external threading of the sleeve. A split collar assembly is located on the stem above the sleeve. The stem has a greater diameter itself, and/or via a nut, at a lower portion of the stem (below the sleeve) relative to the upper portion of stem. The plug stem is designed to pass through the yoke bushing making it possible to perform the normal open-close operation and grinding operation independently.
1. An angle valve apparatus having a yoke, a stem traveling through the yoke, a plug at a lower end of the stem, and further wherein the plug is configured to engage a valve seat, comprising:
a stem sleeve within the yoke, wherein said stem sleeve surrounds the stem at an upper end of the stem opposite the plug, wherein a lower portion of said stem sleeve is configured to motivate movement of the plug;
a radial bearing located between the stem and said stem sleeve, wherein the radial bearing is configured to allow rotational movement between the stem and said stem sleeve;
a split collar assembly located on the upper end of the stem;
a threaded nut on a lower end of the stem, wherein the threaded nut is located below the lower portion of said stem sleeve.
2. The apparatus according to claim 1 , further comprising a yoke bushing threaded to an external surface of said stem sleeve, wherein the yoke bushing is housed within the yoke.
3. The apparatus according to claim 2 , further comprising a hand wheel coupled to the yoke bushing.
4. The apparatus according to claim 3 , further comprising a handle configured to rotate the stem and therefore the plug against scale on the valve seat.
5. The apparatus according to claim 4 , further comprising:
a stem clamp engaging said stem sleeve wherein said stem clamp is configured for anti-rotation of said stem sleeve relative to the stem.
6. A method for grinding scale from a valve seat of an angle valve, wherein the angle valve has a stem, comprising the steps of:
seating a plug on the valve seat by thrusting a sleeve;
wherein the step of seating the plug on the valve seat by thrusting the sleeve comprises the steps of:
driving the sleeve axially;
moving the stem connected to the plug towards the valve seat;
applying a torque to obtain a load between the plug and the valve seat; rotating a hand wheel; and
transferring thrust from the sleeve to the stem by a split collar assembly located on the stem and a threaded nut located on the stem;
adjusting the load between the plug and the valve seat to keep the torque toward a maximum possible torque capable of being driven; and
rotating the stem inside the sleeve for grinding the valve seat.
7. The method according to claim 6 , wherein the steps of applying the torque to obtain the load and adjusting the load comprises the step of applying a torque to a hand wheel.
8. The method according to claim 7 , wherein the step of rotating the stem inside the sleeve for grinding the valve seat further comprises the step of:
rotating a handle connected to the stem; and
rotating the stem and the plug relative to the sleeve.
9. The method according to claim 6 , further comprising the step of preventing rotation of the sleeve while rotating the stem inside the sleeve.