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ASME SEC VIII D1 MA APP 14

APPENDIX14

INTEGRAL FLAT HEADS WITH A LARGE,SINGLE, CIRCULAR,CENTRALLY LOCATED OPENING

14-1SCOPE

14-1(a)In accordance with UG-39(c)(1),?at heads

which have a single,circular,centrally located opening

that exceeds one-half of the head diameter shall be

designed according to the rules which follow.The

shell-to-?at head juncture shall be either integral,as

shown in Fig.UG-34sketches(a),(b-1),(b-2),(d),

and(g),or a butt weld,or a full penetration corner

weld similar to the joints shown in Fig.UW-13.2

sketches(a),(b),(c),(d),(e),and(f).When Fig.UW-

13.2sketches(c)and(d)are used,the maximum wall

thickness of the shell shall not exceed3?8in.(10mm)

and the maximum design metal temperature shall not

exceed650°F(343°C).The central opening in the?at

head may have a nozzle which is integral or integrally

attached by a full penetration weld or may have an

opening without an attached nozzle or hub.

14-1(b)A general arrangement of an integral?at

head with or without a nozzle attached at the central

opening is shown in Fig.14-1.

14-1(c)The head thickness does not have to be

calculated by UG-34rules.The thickness which satis?es

all the requirements of this Appendix meets the require-

ments of the Code.

14-2NOMENCLATURE

14-2(a)Except as given below,the symbols used in

the equations of this Appendix are de?ned in2-3.

A p outside diameter of?at head and shell,in.(mm)

B n p diameter of central opening(for nozzle,this is

inside diameter and for opening without nozzle,

diameter of opening),in.(mm)

B s p inside diameter of shell(measured below ta-

pered hub,if one exists),in.(mm)

(E?)*p slope of head with central opening or nozzle

times the modulus of elasticity,disregarding the

interaction of the integral shell at the outside

diameter of the head,psi

M H p moment acting at shell-to-?at head juncture,in.-

lb(N W m)

P p internal design pressure(see UG-21),psi(kPa)

t p?at head nominal thickness,in.(mm)

B1,F,S H,S R,S T,V,f,g o,g1,and h o are de?ned

in2-3.These terms may refer to either the shell-to-

?at head juncture or to the central opening-to-?at head

juncture and depend upon details at those junctures.

14-3DESIGN PROCEDURE

14-3(a)Disregard the shell attached to the outside

diameter of the?at head and then analyze the?at head

with a central opening(with or without a nozzle)in

accordance with these rules.

14-3(a)(1)Calculate the operating moment M o

according to2-6.(There is no M o for gasket seating

to be considered.)The formulas in Appendix2for

loads(2-3)and moment arms(Table2-6)shall be

used directly with the following de?nitions and terms

substituted for terms in Appendix2:

Let C p G p inside diameter of shell B s,in.(mm);

B p B n,in.(mm),where B n is as shown in Fig.14-

1depending on an integral nozzle or no nozzle.

The moment arm h g in Table2-6will be equal to

zero when using the rules of this Appendix.The M G

moment will therefore be equal to zero.

14-3(a)(2)With K p A/B n,use2-7to calculate

the stresses S H,S R,and S T.The S H and S R stresses

are equal to zero for the case of an opening without

a nozzle.

14-3(b)Calculate(E?)*:

14-3(b)(1)for an integrally attached nozzle,

(E?)*p

0.91(g1/g o)2B1V

f h o

S H

14-32001SECTION VIII—DIVISION114-3

FIG.14-1INTEGRAL FLAT HEAD WITH LARGE CENTRAL OPENING 14-3(b)(2)for an opening without a nozzle,

(E?)*p(B n/t)S T

where g o,g1,B1,V,f,h o,and B n all pertain to the

opening in the?at head as described in14-3(a).

14-3(c)Calculate M H:

M H p

(E?)*

1.74h o V

g o3B1

(E?)*

M o

(1+Ft/h o)

where h o,V,g o,B1,and F refer to the shell attached to the outside diameter of the?at head.

**For some of the terms of the above equation(s),it may be necessary to convert millimeters to meters to obtain a rational result in SI units.

14-3(d)Calculate X1:

X1p

M o?M H(1+Ft/h o)

M o

where F and h o refer to the shell.

14-3(e)Calculate stresses at head/shell juncture and opening/head juncture as follows:

14-3(e)(1)Head/Shell Juncture

Longitudinal hub stress in shell

S HS p(X1)(E?)*

1.10h o f

(g1/g o)2B s V

where h o,f,g o,g1,B s,and V refer to the shell. Radial stress at outside diameter

S RS p

1.91M H(1+Ft/h o)

B s t2

0.64FM H

s o

0114-3APPENDIX14—MANDATORY14-5 where B s,F,and h o refer to the shell.

Tangential stress at outside diameter

S TS p

(X1)(E?)*t

B s

0.57(1+Ft/h o)M H

B s t2

0.64FZM H

B s h o t

where B s,F,and h o refer to the shell,and

Z p

K2+1

K2?1

14-3(e)(2)Opening/Head Juncture

Longitudinal hub stress in central opening

S HO p X1S H

Radial stress at central opening

S RO p X1S R

Tangential stress at diameter of central opening

S TO p X1S T+

0.64FZ1M H

B s h o t

where F,B s,and h o refer to the shell,and

Z1p

2K2

K2?1

14-3(f)The calculated stresses above shall meet the

allowable stresses in2-8.

14-4DATA REPORTS

When all the requirements of this Division and the

supplemental requirements of this Appendix have been

met,the following notation shall be entered on the

Manufacturer’s Data Report under Remarks,“Con-

structed in Conformance with Appendix14,Integral

Flat Heads with a Large,Single,Circular,Centrally-

Located Opening.”

14-5EXAMPLES

Examples illustrating use of the rules of this Appendix

are as follows.

14-5(a)Example(a)

**For some of the terms of the above equation(s),it may be

necessary to convert millimeters to meters to obtain a rational result

in SI units.

14-5(a)(1)Introduction.A cylindrical vessel(with

a72in.O.D.and a70in.I.D.)has an integral?at

head with a large centrally located opening with a40

in.diameter.A nozzle is attached to the opening.The

wall thickness of the nozzle is9?16in.Both the head/

shell and the opening/head details of the transition are

shown in Fig.14-2.The design pressure of the vessel

is100psi with a design temperature of100°F.The

vessel is fabricated from304stainless steel with an

allowable stress of18.8ksi.The thickness of the?at

head https://www.sodocs.net/doc/1818634158.html,ing the rules above determine if the

vessel design is acceptable.

This Example was performed using computer soft-

ware.The Example was generated by performing the

entire calculation without rounding off during each

step.Accuracy of the?nal results beyond three signi?-

cant?gures is not intended or required.

14-5(a)(2)Solution

(a)Input Data

A p outside diameter of?at head and shell p72in.

B n p diameter of central opening p40in.

B s p inside diameter of shell p70in.

P p internal design pressure p100psi

g on p thickness of nozzle above transition p0.563in.

g1n p thickness of nozzle at head p1.125in.

g os p thickness of shell below transition p1in.

g1s p thickness of shell at head p2in.

h n p length of nozzle transition p2in.

h s p length of shell transition p3in.

n p subscript for nozzle at central opening

s p subscript for shell at outside diameter of head

t p nominal thickness of?at head p3in.

(b)Calculate parameters to determine chart val-

ues from Appendix2:

gr n p

g1n

g on

gr s p

g1s

g os

h on p?B n g on p4.75in.

h os p?B s g os p8.37in.

hr n p

h n

h on

p0.421

hr s p

h s

h os

p0.359

F n p0.843

F s p0.857

V n p0.252

V s p0.276

f n p1.518

f s p1.79

14-5APPENDIX14—MANDATORY14-5 B1n p B n+g on p40.563in.

(E?)*p 0.91?g1n g on?2B1n V n

f n h on

S H p269,584

in.2

(g)Calculate M H using the geometry at the shell: B1s p B s+g os p71in.

M H p

(E?)*

1.74h os V s

g os3B1s

(E?)*

M0?1+F s t h os?

p1,792,262in.-lb

(h)Calculate X1using the geometry at the shell:

X1p M0?M H?1+F s t h os?

p0.376

(i)Calculate stresses at the head/shell juncture using the geometry at the shell:

Longitudinal hub stress in the shell

S HS p 1.10h os f s

?g1s g os?2B s V s X1(E?)*p21,621

in2

Radial stress at outside diameter of shell

S RS p 1.91M H?1+F s t h os?

B s t2

0.64F s M H

B s h os t

p7663

in2

Tangential stress at outside diameter of shell

S TS p X1(E?)*t

B s

0.57?1+F s t h os?M H

B s t2

0.64F s ZM H

B s h os t

p3286lb in2

(j)Calculate stresses at the opening/head junc-ture using the geometry at the shell

Longitudinal hub stress at central opening

S HO p X1S H p19,672

in.2

Radial stress at central opening

S RO p X1S R p3114

in.2

Tangential stress at diameter of central opening

S TO p X1S T+

0.64F s Z1M H

B s h os t

p9362

in.2

(k)Allowable stress from2-8and Section II,

Part D:

S f p18,800

in.2

(l)Computed versus allowable stress for the

head/shell juncture:

S HS p21,621

in.2

≤1.5S f p28,200

in.2

S RS p7663

in.2

≤S f p18,800

in.2

S TS p3286

in.2

≤S f p18,800

in.2

S HS+S RS

p14,642

in.2

≤S f p18,800

in.2

S HS+S TS

p12,454

in.2

≤S f p18,800

in.2

(m)Computed versus allowable stress for the

opening/head juncture:

S HO p19,672

in.2

≤1.5S f p28,200

in.2

S RO p3114

in.2

≤S f p18,800

in.2

S TO p9362

in.2

≤S f p18,800

in.2

S HO+S RO

p11,393

in.2

≤S f p18,800

in.2

S HO+S TO

p14,517

in.2

≤S f p18,800

in.2

The computed stresses meet the requirements;there-

fore,the design meets the Appendix14rules

14-5(b)Example(b)

14-5(b)(1)Introduction.A cylindrical vessel(with

a22.5in.O.D.and a22in.I.D.)has an integral?at

head with a large centrally located opening with a16

in.diameter.No nozzle is attached to the head at the

14-5APPENDIX14—MANDATORY14-5

H p0.785B s2P p94,985lb

H D p0.785B n2P p50,240lb

H T p H?H D p44,745lb

R p B s?B n

p3in.

h D p R p3in.

h T p R

p1.5in.

M D p H D h D p150,720in.-lb

M T p H T h T p67,117in.-lb

M0p M D+M T p217,837in.-lb (e)Calculate stresses using2-7:

S T p YM0

t2B n

p15,761

in.2

Note that for an opening without a nozzle attached the longitudinal hub stress and the radial stress are equal to zero.

(f)Calculate(E?)*for the condition of an opening without a nozzle,using the geometry at the opening:

(E?)*p?B n t?S T p112,077lb in.2

(g)Calculate M H using the geometry at the shell:

B1s p B s+g os p22.25in.

M H p

(E?)*

1.74h os V s

g os3B1s

(E?)*

M0?1+F s t h os?

p15,105in.-lb

(h)Calculate X1using the geometry at the shell:

X1p M0?M H?1+F s t h os?

p0.87

(i)Calculate stresses at the head/shell juncture using the geometry at the shell:

Longitudinal hub stress in the shell

S HS p 1.10h os f s

?g1s os?2B s V s X1(E?)*p20,789

in2

Radial stress at outside diameter of shell

S RS p

1.91M H?1+F s t h os?

B s t2

0.64F s M H

B s h os t

p561

in2

Tangential stress at outside diameter of shell

S TS p

X1(E?)*t

B s

0.57?1+F s t h os?M H

B s t2

0.64F s ZM H

B s h os t

p10,060

in2

(j)Calculate stresses at the opening/head junc-

ture using the geometry at the shell:

Tangential stress at diameter of central opening

S TO p X1S T+

0.64F s Z1M H

B s h os t

p14,021

in.2

(k)Allowable stress from2-8and Section II,

Part D:

S f p18,800

in.2

(l)Calculate stress margins for the head/shell

juncture:

S HS p20,789

in.2

≤1.5S f p28,200

in.2

S RS p561

in.2

≤S f p18,800

in.2

S TS p10,060

in.2

≤S f p18,800

in.2

S HS+S RS

p10,675

in.2

≤S f p18,800

in.2

S HS+S TS

p15,425

in.2

≤S f p18,800

in.2

(m)Calculate stress margins for the opening/

head juncture:

S TO p14,021

in.2

≤S f p18,800

in.2

The computed stresses meet the requirements;there-

fore,the design meets the Appendix14rules.

ASME SEC VIII D1 MA APP 14

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