API STD 600:2001 pdf download

API STD 600:2001 pdf download.Bolted Bonnet Steel Gate Valves for Petroleum and Natural Gas lndustries.
5.3.4 Openings
Tapped openings are pi’ohibited unless specified by the purchaser. All openings shall be in accordance with 5.12.
When tapped openings are permitted for testing, they shall not be larger than ON 15.
5.4 Bonnet dimensions
5.4.1 The bonnet stem hole shall be designed to have proper clearance for stem guiding and for the pevention of
packing extrusion.
5.4.2 The bonnet shall include a conical stem backseat in one of the following forms:
— a bushing:
— an integral surface in the case of an austenitic stainless steel valve:
— an austenitic stainless steel or hardface weld deposit with a minimum thickness of 1,6 miii.
5.4.3 The restrictions of 5.3.4 on openings also apply to the bonnet.
5.4.4 Bonnets shall be one piece castings or forgings subject to the same requirements and eccep1ions as spec• itied in 5.3.1.3.
5.4.5 The gland bolting shall not be anchored to the bonnet or yoke through a fillet welded attachment or stud welded pins. The anchor design shall not include slotted holes or brackets which do not shackle gland bolting during repacking.
5.5 Bonnet-to-body joint
5.5.1 The bonnet-to-body joint shall be a flange and gasket type.
5.5.2 For PN 20 valves, the bonnet-to-body jo4nl shall be one of the following types which are illustrated in figure 5 of 1507005-1:1992:
—Type A, flat face;
—Type B, raised face;
—Types C and D, tongue and groove;
— Types E and F, spigot and recess;
— Type J, ring joint.
5.5.3 For valves having nominal pressure greater than PN 20 the bonnet-to-body joint shall be in accordance with
5.5.2, except that the Type A, ftat face, join; is not permitted.
5.5.4 The bonnet flange gasket shall be suitable for the temperature range — 29”C to 538°C and shall be one of
the following:
— solid metal, corrugated or flat:
— filled metal jacketed, corrugated or flat;
— metal ring joint:
5.8 Stem and stem nut
5.8.1 The minimum stem diameter. d5. at the time of manufacture shall be in accordance with table 6. The minimum stem diameter applies to the stem in the packing area and to the mayor diameter of the trapezoidal stem thread However, the major diameter of the stem thread may be reduced, at the manufacturer’s option, by no more than 1.6 mm The stem surface area in contact with the packing shaH have a surface finish. Ra of 0.60 jim or smoother.
5.8.2 Stems shall have a gate attachment means at one end and an external trapezoidal style thread form at the other, Stem nuts shall be used for handwheel attachment and to drive the operating stem thread.
5.8.3 The stem-to-stem nut threads shall be of trapezoidal form as specified in ASME Bi .5 or ASME Bi .8, with nominal dimensional variations allowed. Stern threads shall be left-handed so that a direct operated handwheel rotated in a clockwise direction will close the valve.
5.8.4 The stem shall be one-piece wrought material. Wekied fabrication is not permitted.
5.8.5 The stem end that connects to a gate shall be in the form of a tee. However, for a double disc gate, the end connection may be threaded.
5.8.6 The stem connection shall be designed to prevent the stem from turning or from becoming disengaged from the gate while the valve is in service.
5.8.7 The stem design shall be such that the strength of the stem to gate connection and the part of the stem within the valve pressure boundary shall, under axial load, exceed the strength of the stem at the root of the operating thread.
5.8.8 The one-piece stem shall Include a conical or spherical raised surface that will seat against the bonnet backseat when the gate is at its full open position. A stem-bonnet backseat is a requirement of this International Standard, and as such, is not meant to imply a manufacturer’s recommendation that it may be used for the purpose of adding or reptacing packing while the valve is under pressure.
5.8.9 The stem nut design shall allow for the removal of the handwtieel while keeping the stem (and disc) in a fixed position.