08-16-2017, 10:29 PM
Check Valves: Wafer, Wafer-Lug, and Double Flanged Type
[attachment=865]
General
SCOPE
This standard covers design, material, face-to-face dimensions,
pressure-temperature ratings, and examination, inspection,
and test requirements for gray iron, ductile iron, steel,
and alloy single and dual plate check valves. Valve configurations
include wafer, wafer-lug, and double flanged type with
facings that will permit installation between ASME and MSS
flanges that conform to the standards and specifications listed
in section 2.
VALVE NOMENCLATURE
The standard nomenclature for valve parts is shown in Figures
1, 2, 3, and 4. These figures illustrate some wafer, waferlug
and double flanged type check valve designs. Although
Figures 1, 2, 3, and 4 show typical designs, they are not to be
construed as precluding other available designs that comply
with the requirements of this standard.
Pressure-Temperature Ratings
VALVE RATING
The pressure-temperature rating of the valve will be the
lesser of the body rating or the seat rating.
BODY RATING
The valve body rating for various body materials shall be
as follows:
a. Gray iron: The pressure-temperature rating for the applicable
flange class as specified in ASME B16.1.
b. Ductile iron: The pressure-temperature rating for the
applicable flange class as specified in ASME B16.42.
c. Steel, nickel alloy or special alloy: The pressure-temperature
rating for Standard Class valves made of identical
material as listed in ASME B16.34.
SEAT RATING
The pressure-temperature rating of the valve seat for valves
furnished with resilient seating materials shall be specified by
the manufacturer. Temperature limitations of the seat material
shall be marked on the nameplate, as required in 7.1.2.
Design
BODY
1.1
The minimum body-wall thickness shall conform to
those shown in Tables 1A and 1B.
1.2
The face-to-face dimensions of valves (including
valves with ring-joint facings) shall conform to those shown
in Tables 2A and 2B.
1.3
The valve shall have a wafer, wafer-lug, or double
flanged body as specified in the purchase order. (Double
flanged valves are available where nut space between flanges
is adequate).
1.4
Valves larger than NPS 24 in Classes 150, 300, 400,
and 600 shall have body-flange bolt patterns suitable for the
wafer-lug or double flanged type, outside diameters suitable
for the wafer type, and gasket surface dimensions compatible
with the flange standards specified in the purchase order.
1.5
Ring-joint grooves shall conform to the dimensions
shown in either ASME B16.5 or ASME B 16.47 as applicable
[attachment=865]
General
SCOPE
This standard covers design, material, face-to-face dimensions,
pressure-temperature ratings, and examination, inspection,
and test requirements for gray iron, ductile iron, steel,
and alloy single and dual plate check valves. Valve configurations
include wafer, wafer-lug, and double flanged type with
facings that will permit installation between ASME and MSS
flanges that conform to the standards and specifications listed
in section 2.
VALVE NOMENCLATURE
The standard nomenclature for valve parts is shown in Figures
1, 2, 3, and 4. These figures illustrate some wafer, waferlug
and double flanged type check valve designs. Although
Figures 1, 2, 3, and 4 show typical designs, they are not to be
construed as precluding other available designs that comply
with the requirements of this standard.
Pressure-Temperature Ratings
VALVE RATING
The pressure-temperature rating of the valve will be the
lesser of the body rating or the seat rating.
BODY RATING
The valve body rating for various body materials shall be
as follows:
a. Gray iron: The pressure-temperature rating for the applicable
flange class as specified in ASME B16.1.
b. Ductile iron: The pressure-temperature rating for the
applicable flange class as specified in ASME B16.42.
c. Steel, nickel alloy or special alloy: The pressure-temperature
rating for Standard Class valves made of identical
material as listed in ASME B16.34.
SEAT RATING
The pressure-temperature rating of the valve seat for valves
furnished with resilient seating materials shall be specified by
the manufacturer. Temperature limitations of the seat material
shall be marked on the nameplate, as required in 7.1.2.
Design
BODY
1.1
The minimum body-wall thickness shall conform to
those shown in Tables 1A and 1B.
1.2
The face-to-face dimensions of valves (including
valves with ring-joint facings) shall conform to those shown
in Tables 2A and 2B.
1.3
The valve shall have a wafer, wafer-lug, or double
flanged body as specified in the purchase order. (Double
flanged valves are available where nut space between flanges
is adequate).
1.4
Valves larger than NPS 24 in Classes 150, 300, 400,
and 600 shall have body-flange bolt patterns suitable for the
wafer-lug or double flanged type, outside diameters suitable
for the wafer type, and gasket surface dimensions compatible
with the flange standards specified in the purchase order.
1.5
Ring-joint grooves shall conform to the dimensions
shown in either ASME B16.5 or ASME B 16.47 as applicable