Acceptance Criteria for Liquid Penetrant Testing -LPT

 

Acceptance Criteria for Liquid Penetrant Testing -LPT as per ASME , AWS and API standards

Liquid penetrant testing simply called as PT. Sometimes Dye Penetrant Testing is a surface defect detection NDT  method and is more sensitive to all kind of surface defects, such as cracks , porosity, hot tears, laps, etc.

The NDT methods are trained by NDT Training Institutes with their NDT courses, and the LPT is one among the basic Non Destructive Testing Methods.

Penetrant testing -AQC

Various international standards for Liquid Penetrant Testing are as below

ASME Boiler and Pressure Vessel Code BPVC- Section V – Article 6 and Article 24

ASTM E-1417 (ASTM Standard)

ASTM E-165 (Penetrant Testing Standard for general Industry ASTM Standard)

ISO 3452-1 (ISO Standard)

SAE AMS 2644 (Aerospace Standard)

AS 2062 (Australian Standard )

DIN EN 571

The Indications are evaluated as per Clients Acceptance Criteria or the Product Standard in conformance with the clients acknowledgement .

Fluorescent penetrant testing

Few examples of product standards are as below :

AWS D1.1 – Structural Steel Welding Standards

API 1104 – Pipeline Welding

ASME BPVC section VIII – Pressure Vessel

ASME B 31.1 – Process Piping

ASME B 31.3 – Power Piping

ASME B16.34 – Valves, and lot more

Acceptance Criteria for Liquid Penetrant Testing -LPT from the above mentioned standards are given below for your convenience.

DYE PENETRANT INSPECTION – API 1104

Rejection Criteria

Liner Indications

Indications > 1/16” (1.59mm) shall be considered as Relevant Indication, Relevant indications are rejectable if:

Evaluated as crater cracks or star cracks and > 5/32” (3.96mm) in length.

Evaluated as cracks other than crater cracks or star cracks.

Evaluated as IF and >1” (25.4mm) in total length in a continuous 12” (304.8 mm) weld or >8% of the weld length.

Rounded Indications:

For evaluation, the maximum dimension of rounded indications shall be considered as it size.  Indications are reject able as defects if:

Individual indication > 1/8” (3.17mm)

Distribution of scattered rounded indications exceed concentration API 1104 fig. 18 or 19.

Clustered rounded indications > 1/2” (12.7mm)

Combined length of clustered indications > 1/2” in any 12” (304.8mm) weld.

Any individual indication in a cluster > 1/16” (1.59mm).

DYE PENETRANT INSPECTION – ANSI/ASME B31.1

Liner indication:

Any crack or liner indication.

Rounded indications:

Indications is dimensions > 3/16” (5.0mm).

Four or more rounded indication in a line separated by 1/16” (2.0mm) or less edge to edge.

Ten or more rounded indication in any 6 sq. in. (3870mm2) of surface with the major dimension of this area not to exceed 6 in. (150mm).

DYE PENETRANT INSPECTION – ANSI/ASME B31.3

Liner indications:

Any cracks or linear indications.

Rounded indications:

Pending verification from ANSI.  Until otherwise stipulated by ANSI B31 Committee, apply B31.1 criteria for rounded indications.

DYE PENETRANT INSPECTION – ASME Section VIII Div. 1

Relevant linear indication >1/16” (1.59mm)

Relevant rounded indications >3/16: (4.77mm)

Four or more rounded indications in a line separated by 1/16” (1.59mm) or less (edge to edge)

DYE PENETRANT INSPECTION – AWS D1.1

Refer the table below from AWS D1.1 , for the acceptance criteria for Liquid Penetrant Testing, the acceptance criteria for visual testing also applies for Liquid / Dye penetrant testing as per AWS D1.1 .

visual inspection acceptance criteria

This method is applicable in almost all material except for material with porous surface, it is suitable for both casting/raw material and welding inspection.

For more details ping me at watsapp number 8668082413 or visit https://aqcinspection.com/training/.

Remember Penetrant Testing is an low cost and more easily adaptable method for all kinds of industry, but without proper training and certification for specific NDT method the PT test is not reliable.

NDT courses are readily available in training institutes in all major cities around  the world to train this simple testing method.

Visit our technical and career updates at our Blog site https://advancedqualitycentre.blogspot.com . or https://ndtcenter.blogspot.com

Location: 116-B, 5th Street Extension, Dr Rajendra Prasad Rd, Behind Kalyan Jewellers, 5th Street Extension, Coimbatore, Tamil Nadu 641012, India

Comments

  1. Stock Market Training Center in LucknowJuly 1, 2022 at 1:29 PM

    Non Destructive Testing Certification
    Find the right instructor for you. Choose from many topics, skill levels, and languages. Join millions of learners from around the world .join now for more guidance - https://www.uptti.com/non-destructive-testing-training-courses/

    ReplyDelete

Post a Comment

Popular posts from this blog

Discontinuities in Ultrasonic Testing in NDT

Image
 This blog will discuss types of discontinuities that can be evaluated with the ultrasonic testing in NDT method. Discontinuities can be divided into three general categories inherent, processing and service Inherent discontinuities are usually formed when the metal is molten. Inherent wrought discontinuities relate to the melting and solidification of the original ingot before it is formed into slabs, blooms and billets. Inherent cast discontinuities relates to the melting, casting and solidification of a cast article. Usually caused by inherent variables such as inadequate feeding, gating, excessive pouring temperature or entrapped gases. Processing discontinuities are usually related to the various manufacturing process such as machining, forming, extruding, rolling, welding, heat treating and plating. Service discontinuities are related to the various service conditions such as stress, corrosion, fatigue and erosion. During the manufacturing process, many d...
Read more

NDT on Shafts

Image
  Non Destructive Testing,NDT on Shafts is considered essential , because the shafts are mostly made as load bearing structures, any defects such as cracks will propagate more during acting of load and eventually will cause failure. The most possible defects in shafts are Cracks and Pipes , which is shown below The Non Destructive methods preferred for defect detection on raw material shafts are Ultrasonic Testing, Magnetic Particle testing / Eddy Current Testing / Magnetic Flux Leakage method. We have not discussed about other NDT methods such as Liquid Penetrant testing & Radiographic testing because for raw material inspection. These methods will be cost effective for raw material testing  ( i.e. most costly and labor intensive, also there is possibility of missing out the cracks in radiography testing due to orientation of crack ) The Defect wise identification method is given as below  , Internal Defect ( Piping ) – Ultrasonic Testing Surface Defects  (C rac...
Read more

Standards for Welding Positions

Image
  Standards for Welding Positions : It is very important for the Weld Inspector  to know the position , or location of a joint relative to the horizon, because it may determine what welding process, methods, and techniques can be used. Welding is usually easiest when the welder can work on a joint located on a flat, horizontal surface, such as on a table or bench. However, joints in the field may be located in a variety of positions relative to the welder and to the horizon, as shown below.  1)  Welding positions – AWS D1.1, European Welding Standard EN 287 – 1, ASME IX: 2) Welding Positions – Butt, Fillet and Piping Welds: Flat Butt Weld Position – 1G In this position, the axis line of the weld must  not incline more than 15°  from the horizon and the face of the weld must be on top. Welders often refer to the flat-position welding by the nonstandard term  downhand welding. Horizontal Butt Weld Position – 2G In this position, both plates are perpendic...
Read more