Globe Valves
BS 1873
CAST STEEL BODY, OUTSIDE SCREW AND YOKE, RISING STEM, NON-RISING OPERATOR, RENEWABLE SEATS, REMOVABLE YOKE SLEEVE, BACKSEAT FOR REPACKING UNDER PRESSURE.
REMARKS:
A lantern ring is supplied upon request, in this case the stuffing box shall be drilled, tapped and fitted with an 1/4” NPT plug or grease fitting.
INSTALLATION REMARKS:
Globe valves are best fit for vertical stem / horizontal flow installation. Special cases can be evaluated and developed on request.
Description
OPERATOR
The spoked handwheel is fabricated from steel pipe. The hub has a square hole for coupling with the stem, and for large sizes the hube is coupled with the yoke sleeve by means of a tongue (like gate valves).
GLAN AND FLANGE
They are in forged steel and are supplied in two pieces, self aligning design in order to allow the gland to slide parallel to the stem even if the eyebolts are unevenly tightened.
GLAND BOLTS AND NUTS
The forged steel gland bolts are of the eyebolt type which can be swung outward for ease of gland repacking. They are fixed to the bonnet by hinge pins.
BONNET BOLTING
Bonnet studs and nuts are manufactured from alloy steel to the relevant ASTM standard. The body to bonnet connection is designed according to ASME VIII DIV 1 standard.
BODY
The body is in carbon or stainless steel and is also available in many other CRA. It is carefully designed for total reliability and simple maintenance. The basic dimension, i.e. wall thickness, face to face and flanges comply with the relevant BS and ASME standards. The body-to-bonnet flange is circular. The body-to-bonnet joint are male-and-female on Class 150 and 300 and ring joint on Class 600 and above. The body is basically supplied with renewable seats. Bosses are provided for draining connections. The internal surfaces in contact with the fluid can be fully lined or cladded (for larger sizes only) for improved corrosion or erosion resistance.
BONNET
As the body, the bonnet is in carbon or stainless steel and is available in many other CRA. It is machined to accept yoke sleeve and incorporates a stuffing box sized in accordance with the BS standard. Lifting lugs can be provided integrally cast on the bonnet surface.
BONNET BUSHING
The bonnet bushing or backseat is part of the valve trim. Its design allows valve repacking without valve’s bleeding or draining. Hardfacing can be provided on stem seating surface.
STEM
The stem is part of the trim and is available in a wide range of material in accordance to BS1873, API 600 or customer’s requirements. The stem is provided with a ground backseat in order to ensure a perfectly tight seal to the stuffing box when the valve is fully open. The stem is highly finished in order to minimize friction and prevent damage to the packing. The thread is trapezoidal ACME type. All the stem sizes comply with the BS 1873 standard.
SEAT RING
Threaded and seal-welded seat ring is supplied as a standard. The seats are part of the trim of the valve. They can be simply threaded for easy installation and dismantling. Special attention is given to the seating surface which is ground and lapped for a tight seal.
DISC
The disc is the main part of the trim. It is connected to the stem by means of a swiveling half rings coupling and is guided in the body from 4” and above. The standard sealing profile is a spherical surface seating against a conical seat. If required a conical to conical seating can be supplied, and for flow throttling operations a regulating disc is adopted, shaped in order to give a linear opening. The stop check execution shows an externally guided disc, disconnected from the stem. A cladding or lining can be applied to larger discs to improve its resistance against erosive and corrosive environments.
