Valves and valve actuation – Reciprocating valve – Diaphragm
Patent
1991-09-26
1993-09-21
Rosenthal, Arnold
Valves and valve actuation
Reciprocating valve
Diaphragm
2513352, 137863, F16K 712
Patent
active
052462048
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a sampling valve comprising a valve body having an axial bore, a valve stem axially displaceable in the bore, and a stretchable hollow valve plug that is mounted on the valve stem, the valve stem being axially displaceable within the valve plug, the front end of the valve stem pushing the valve plug in its stretched position wherein the latter closes against a valve seat coaxial with the bore and extending from an annular channel communicating with a pair of hose connection branches of the valve body.
Such a valve structure is disclosed in the published documents of Applicant's Danish Patent Application No. 2732/86. An important feature of this valve is that the valve plug is firmly bonded to the wall of the axial bore at least in its area adjacent the annular channel, for the purpose of preventing liquid from penetrating between the valve body and the plug. Such a risk is involved with a previously known sampling valve, cf. Danish Patent Specification No. 147,119, in which the plug is firmly bonded to the forward end portion of the stem and forms a plunger operating in the forward end of the bore.
In the latter case the plug may be withdrawn from the bore together with the valve stem, e.g. for renewal or for allowing the interior of the valve to be inspected, whereas in the former case such a withdrawal or removal of the plug from the bore is more complicated because its bonding to the bore wall must be broken. The plug may be thereby further damaged so that it cannot be used again.
Swiss patent specification No. 635 407 discloses a valve comprising a stretchable hollow valve plug, the front end of a valve stem pushing the valve plug in its stretched position whereby a collar at the open end of the valve plug is forced against an abutting sealing surface and the valve plug closes against a valve seat coaxial with the valve stem.
The sampling valve of the invention differs from the known structures by the feature that the valve plug rests with a collar at its open end against an abutting surface in the bore and in that on the inner surface of the valve plug member a bead is provided which in the mounted position of the member projects into a circumferential groove formed in the valve stem and having an axial length that is sufficient to permit the stretching of the valve plug from its open to its closed position.
Under normal operating conditions the groove of the valve stem does not prevent the bead from moving axially backwards and forwards relative to the stem when the plug is stretched and allowed to retract, respectively. However, when it is desired to remove the plug for inspection or other purposes, the stem may simply be withdrawn axially out of the bore, thereby causing the plug to be carried along after the bead has come into contact with the forward side wall of the groove. When the plug has got clear of the bore, it may easily be snapped free from the stem, if so desired.
The invention will now be more fully described with reference to the drawing, in which
FIG. 1 is a side elevation and axial section of a preferred embodiment of the valve in its closed position, and
FIG. 2 a similar view of the valve when open.
In the illustrated embodiment the valve comprises a body or casing 1 adapted to be firmly mounted in the wall 2 of a tank or pipe containing a liquid from which samples shall be taken from time to time. A pair of hose connection branches 3, communicate at their inner ends with an annular channel 4 adjacent a central valve seat 5.
A bore 6 in body 1 is co-axial with the valve seat, and in this bore a valve stem is axially displaceable. The stem comprises a front or lower portion 7 and a back or upper portion 8 with a threaded connection 9 therebetween.
A stretchable hollow valve plug 10 fits into the forward end of the bore 6 and rests with a collar 11 at its open end against a shoulder in the bore. The plug 10 surrounds the forward end of the stem portion 7 which in FIG. 1 is urged to the left by a helical compression spring 12 so that the plug 10 is stretched
REFERENCES:
patent: 4552336 (1985-11-01), Pastrone
patent: 4720076 (1988-01-01), Hyde
LandOfFree
Sampling valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sampling valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sampling valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1044912