2A1 Chapter 1 ASME Code Calculations: Cylindrical Components

What is the primary focus of Chapter 1 in ASME Code Calculations?

Cylindrical components including piping, tubes, drums, and headers.

What is the maximum allowable working pressure (MAWP)?

The maximum pressure that a component can safely withstand, typically measured in gauge pressure.

What is the minimum thickness for any boiler plate under pressure according to ASME Section I?

6 mm.

What does PG-27 cover in the ASME Code?

It provides formulae to determine the minimum required thickness of cylindrical components under internal pressure.

What is the significance of the safety factor in ASME standards?

It accounts for limitations in testing technology, unusual stress concentrations, non-uniform materials, and material flaws.

What is the minimum required thickness for plates to which stays may be attached?

8 mm.

What does the term 'efficiency' refer to in the context of ASME calculations?

It is a factor used in the formulae for determining the strength of cylindrical components.

What is the formula used to calculate the minimum required thickness of a cylindrical component?

It involves parameters such as outside diameter, maximum allowable working pressure, and maximum allowable stress.

What is the purpose of the ASME Code?

To ensure safe and reliable performance of pressure vessels and boilers.

What does PG-21 state about gauge pressure?

It refers to gauge pressure unless otherwise noted in the calculation formula.

What is the maximum allowable stress value?

It is the maximum stress a material can withstand at the design temperature.

What is the importance of correct units of measure in ASME calculations?

They are crucial for accurate calculations.

What does paragraph PG-6 state about steel plates for boilers?

They must conform to specifications listed in paragraph PG-6.1.

What is the minimum wall thickness for pipes used in cylindrical components under pressure?

6 mm for pipes over 125 mm nominal size.

What is the role of power engineers regarding ASME codes?

They must have a detailed working knowledge of key engineering codes and standards for compliance.

What does PG-27.3 define?

The symbols used in the formulae for calculating thickness and pressure.

What is the purpose of the Boiler and Pressure Vessel Committee?

To establish rules for the safe construction of pressure vessels.

What is the significance of the 2007 ASME Codes mentioned in the chapter?

They provide the basis for the calculations and standards discussed.

What does the term 'weld joint strength reduction factor' refer to?

It is a factor used to account for the reduced strength of welded joints in calculations.

What is the acceptable thickness tolerance for plate material?

Not more than 0.3 mm thinner than the required thickness calculated by Code formula.

What is the role of power engineers in equipment design and upgrades?

They work as team members to ensure compliance with engineering codes.

What does PG-16.4 state about plate material thickness?

Material not more than 0.3 mm thinner than required may be used if manufacturing allows.

What does PG-16.5 state about ordering pipe or tube material?

It shall not be ordered thinner than the required thickness calculated by Code formula.

What is the definition of 'C' in the formulae for cylindrical components?

Minimum allowance for threading and structural stability (mm).

What does 'D' represent in the formulae for cylindrical components?

The outside diameter of the cylinder (mm).

What does 'P' stand for in the cylindrical component calculations?

Maximum allowable working pressure (MPa).

What does 'S' represent in the formulae?

Maximum allowable stress value at the design temperature of the metal.

What is the importance of the 2009 Addenda mentioned in the chapter?

It provides updates and improvements to the 2007 ASME Codes.

What does Paragraph UG-4 state about materials under stress?

Materials subject to stress due to pressure must conform to specifications in Section II, unless permitted otherwise in specific paragraphs.

What is the purpose of ASME Boiler Code Section I and Section VIII?

They require examination of major longitudinal and circumferential butt joints by full radiograph.

What is the joint efficiency (E) for a fully radiographed major longitudinal butt-welded joint?

E = 1.0

What is the joint efficiency (E) for non-radiographed longitudinal butt-welded joints?

E = 0.7, which increases the required plate thickness by 43%.

What does Paragraph UG-20 specify about design temperature for pressure vessels?

The design must consider both maximum and minimum temperatures the vessel will experience.

What is the formula used to determine the minimum required thickness of shells under internal pressure?

The formula in UG-27 is used to calculate the minimum thickness based on maximum allowable working pressure.

What does 't' represent in the formula for minimum required thickness?

't' is the minimum required thickness in millimeters.

What does 'P' represent in the thickness formula?

'P' is the internal design pressure in MPa.

What does 'R' represent in the thickness formula?

'R' is the inside radius of the shell course under consideration in millimeters.

What does 'S' represent in the thickness formula?

'S' is the maximum allowable stress value.

What is the significance of joint efficiency (E) in cylindrical shells?

It reflects the efficiency of the joint in welded vessels or ligaments between openings.

What is the formula for calculating the minimum required thickness of a watertube boiler tube?

t = (PD/(2Sw)) + 0.005D + e

What is the maximum allowable working pressure (MAWP) formula for a tube?

MAWP = (2t/(D - 0.005D)) * (Sw/(D - t))

What is the formula for calculating circumferential stress in thin cylindrical shells?

P = (0.6 PR)/(t SE)

What is the formula for calculating longitudinal stress in thin cylindrical shells?

P = (0.4 PR)/(t SE)

What considerations must be taken for thick cylindrical shells under high internal pressures?

Special considerations as specified in paragraph U-1 (d) are required.

What is the dimensionless factor 'Z' defined in UG-34(b)?

Z considers the ratios of short to long spans.

What is the base of natural logarithms denoted as?

The base of natural logs is denoted as 'e', approximately equal to 2.7182.

What is the significance of the ratio t/R in thick-walled vessels?

As the ratio increases beyond 0.5, a more accurate equation is required to determine the thickness.

What does the term 'strength welded' refer to?

It indicates that the tubes are welded in a manner that provides structural integrity.

What is the importance of checking PG-6 and PG-9 before starting calculations?

They direct you to the correct stress table in ASME Section II, Part D for material specifications.

What material is used in the construction of the vertical boiler?

SA-515-60

What is the joint efficiency for the vertical boiler?

0.85

What is the required shell thickness for the vertical boiler?

11.4 mm

What is the new outside radius of the vertical boiler?

1228.4 mm

What is the maximum allowable working pressure for the seamless steam piping?

6.6 MPa

What is the nominal pipe size of the seamless steam piping?

10 inches

What is the operating temperature for the seamless steam piping?

375°C

What is the material used for the seamless steam piping?

SA-335-P11

What is the maximum allowable working pressure for the welded watertube boiler drum?

8.36 MPa

What is the plate thickness of the tubesheet in the welded watertube boiler drum?

59.5 mm

What is the material used for the tubesheet in the welded watertube boiler drum?

SA-515-60

What is the longitudinal joint efficiency for the tubesheet?

100%

What is the ligament efficiency for the tubesheet in the welded watertube boiler drum?

30%

What is the inside radius of the tubesheet in the welded watertube boiler drum?

475 mm

What is the stress value for SA-209-T1 at 450°C?

101 MPa

What is the efficiency factor (E) for seamless pipes as per PG-27.4?

1.0

What is the formula for calculating the maximum allowable working pressure in cylindrical components?

The formula is based on the lowest number between the drum and the tubesheet.

What section of the ASME code contains formulas for minimum required thickness of pipes and drums?

ASME Section VIII, Division 1, specifically UG-27.

What is the significance of PG-29 in dished head calculations?

It provides the thickness calculation for a blank, unstayed dished head with pressure on the concave side.

What is the formula for calculating the thickness of a dished head?

t = (5PL) / (4.8Sw), where P is maximum allowable working pressure, L is radius, S is maximum allowable working stress, and w is weld joint strength reduction factor.

What are the dimensions specified for manholes in ASME Section PG-44?

Elliptical manholes must be not less than 300mm x 400mm and circular manholes not less than 380mm.

What is the minimum thickness requirement for a head with a flanged-in manhole exceeding 150 mm?

The thickness must be increased by 15% of the required thickness or by at least 3.0 mm, whichever is greater.

What is the formula for calculating the thickness of a full-hemispherical head?

t = (2PL) / (0.2SwP), where P is the maximum allowable working pressure, L is the radius, S is maximum allowable working stress, and w is weld joint strength reduction factor.

What is the minimum thickness requirement for a semi-ellipsoidal head?

It must be at least as thick as the required thickness of a seamless shell of the same diameter.

What is the weld joint strength reduction factor for temperatures below 427°C?

The weld joint strength reduction factor is 1.0.

How is the thickness of a seamless, blank unstayed dished head calculated?

Using the formula from PG-29.1, considering the maximum allowable working pressure and material properties.

What must be calculated to determine if a dished head thickness meets Code requirements?

The thickness of the shell must be calculated using the appropriate formula.

What is the significance of PG-29.6 regarding head thickness?

It states that no head shall be of lesser thickness than that required for a seamless shell of the same diameter.

What is the radius requirement for a dished head in relation to the shell diameter?

The radius must be at least 80% of the diameter of the shell.

What is the maximum allowable working stress for SA-285 A at 250°C?

88.9 MPa.

What is the formula used to calculate the required thickness of a seamless shell?

t = (PD) / (2SE + 2yP), where D is diameter, S is maximum allowable working stress, and y is a material factor.

What does PG-29.2 state about the radius of a dished head?

It shall not be greater than the outside diameter of the flanged portion of the head.

What is the significance of the weld joint strength reduction factor in calculations?

It accounts for the strength reduction due to welding in the material.

What is the thickness requirement for a blank head of a semi-ellipsoidal form?

It must be at least as thick as the required thickness of a seamless shell of the same diameter.

What is the relationship between the thickness of a dished head and the thickness of a seamless shell?

The dished head thickness must meet or exceed the thickness required for a seamless shell of the same diameter.

What is the thickness increase requirement for dished heads with multiple manholes?

The minimum distance between openings must be not less than one-fourth of the outside diameter of the head.

What temperature does the ASME code specify for determining material properties?

The temperature must not exceed the specified limit for the material, such as 250°C for SA-285 A.

What is the formula for calculating the minimum required thickness of a full-hemispherical head?

t = (P L) / (2 S * w) + 0.2

What is the maximum allowable working pressure for a full-hemispherical head with a radius of 190.5 mm?

6205 kPa

What is the significance of checking if the calculated thickness exceeds 35.6% of the inside radius?

To ensure the correct formula has been used.

What does PG-29.12 apply to in the context of hemispherical heads?

Flanged-in manholes.

What is the required thickness formula for a thin spherical shell under internal pressure?

t = (P R) / (2 S * E)

What is the difference between Section VIII-1 and Section VIII-2 in ASME Code?

They contain different rules for the design of spherical shells and heads.

What is the formula for calculating the required thickness of ellipsoidal heads?

t = (P D) / (2 S * E)

What is the ratio of base radius to depth for commonly used ellipsoidal heads?

2:1

What is the required thickness formula for torispherical heads?

t = (0.885 P L) / (S * E)

What is the significance of the joint efficiency factor (E) in head thickness calculations?

It accounts for the strength of the joint in the design.

What is the required thickness formula for thick hemispherical heads?

t = (P R) / (S E)

What is the formula for calculating the thickness of unstayed flat heads?

t = (P D) / (2 S * E)

What is the significance of the ratio ts/L in head thickness calculations?

It determines the minimum specified thickness of the head after forming.

What is the purpose of a flat plate or cover in a pressure vessel?

To serve as an end closure or head of the vessel.