Check valve having a friction free replaceable valve insert check assembly

A check valve has a friction-free replaceable valve insert check assembly. The check assembly includes a poppet on which a spring is mounted engaging an axially moveable seat which in turn engages a seat on the inner end of the poppet biased into engagement by the spring. Upon separation of the inner and outer valve bodies the insert check assembly will freely separate from the valve body for inspection or replacement.

BACKGROUND OF THE INVENTION

The check valve having a replaceable valve assembly of U.S. Pat. No. 4,532,958 is representative of the prior art over which the present check valve is an improvement in that the insert check assembly may be readily inserted or removed without the need to overcome friction between the valve assembly and seals within the valve body.

SUMMARY OF THE INVENTION

The insert check assembly is spaced from the inside wall surface of the inlet body such that it may be freely inserted or removed from the inlet body for inspection or if appropriate replacement. The insert check assembly includes a first seat on a poppet having a coil spring engaging the bottom side of a second seat allowing the first seat to move axially within the passageway of the valve bodies between open and closed positions.

The second seat is positioned on an annular axial inner end edge of the inlet body against a first seal received in an annular recess in the inner end of the inlet body.

A second seal is positioned on the inlet body for engagement with the inner end of the outlet body. The inner ends of the inlet body and the outlet body are threadably engaged.

The insert check assembly thus is insertable in and removable from the inlet body inner end without the need to overcome friction with the passageway side wall of the inlet body. This allows fast inspection or replacement of insert check assemblies without the need of special tools other than a wrench to separate the inlet body from the outlet body. The insert check assembly is self-aligning upon field installation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The valve assembly of this invention is referred to generally by the reference numeral10inFIG. 2and includes an inlet body12and an outlet body14. An insert check assembly16is positioned in the inlet body12as seen inFIG. 4.

The insert check assembly16as seen inFIG. 5includes a poppet18on which a spring20is mounted which engages a seat element22biased into engagement with a seat element24. The poppet18is axially moveable relative to the seat element22. The inlet body12includes an annular recess26which receives an insert seal28. A body seal30is received in an annular recess32on the outer wall surface of the inlet body12. The outlet body14includes an annular shoulder34which engages the seat22pressing it into engagement with the insert seal28in the annular recess26when the valve is fully assembled as seen inFIG. 4.

The outlet body14is threadably attached to the inlet body12through threading36on the outlet body and38on the inlet body with the inner end of outlet body14having an annular shoulder40engaging the body seal30received in the annular groove32.

When attention to the valve assembly is required in the field of use the outlet body14is easily removed from the inlet body12and the insert check assembly16will likely fall out for easy inspection and if appropriate, replacement of the insert check assembly16. It is particularly noted that removal of the insert check assembly does not require tools or overcoming any friction with either the inlet body12sidewall42or any part of the outlet body14. If necessary the insert seal28and body seal30which are O-rings may also be easily replaced in the field.

It can be readily seen fromFIGS. 4 and 5that there is no need for lubricant for installing the O-rings28and30or the insert check assembly16so there is no potential for contaimination associated with the replaceable seals28and30and insert check assembly16. It is also seen that the check assembly16is self-aligning upon field installation.