Truss

STEPS FOR DPT TEST IN TRUSS

The STEPS FOR DPT TEST IN TRUSS discuss in this post. The Dye Penetration Testing (DPT) is a test uses to identify, the discontinuities in welding joints and connections. And uses to detect the cracks, fractures, etc. It is a low cost inspection method known as the Liquid Penetrate Inspection ( LPI ), Dye Penetrant Inspection ( DPI ).

The Cleaner, the Penetrant and the Developer are the three main materials for this DPT testing. These are all the Non toxic chemicals. And Eco friendly materials. Using these Cleaner, the Penetrant and the Developer, the DPT testing carries out.

This Dye Penetration Testing has different names,

  • Liquid Penetrate Inspection ( LPI )
  • Dye Penetrant Inspection ( DPI )
  • Penetration Testing ( PT )

It is a simple test. And easy test to identify the discontinuities in welding joints. Using this DPT TEST ON TRUSS MEMBERS all the surface defects and the flaws are easily identify and rectify. This test carries out without difficulties. This is one of the oldest test for identification of the defects in welding in truss joints and the connections.

STEPS FOR DPT TEST IN TRUSS

There are some important steps for DPT test in truss. This vary by the factors like, the applying system, the size and the components of materials. And the type of discontinuities, environment and the climatic conditions, etc,. The major steps of testing are,

  1. Surface Preparation
  2. Drying After cleaning
  3. Penetrant Application
  4. Penetrant Dwell
  5. Excess Penetrant Removal
  6. Drying
  7. Developer Application
  8. Indication Development
  9. Inspection
  10. Evaluation

The STEPS FOR DPT TEST IN TRUSS are as follows,

1. Surface Preparation

After completions of all the welding for joints and the connections of truss components, the welding slug removes. This performs using mechanical means or by chipping hammers. And cleans with a steel wire brush.

The Surface to examine cleans fully. All the adjacent sides of the welding joints cleans properly up to minimum of twenty centimetre. The joint coated with the primer and the paint removes with the paint remover, wire brush or by mechanical means for testing.

This performs to obtain the accurate results. It must be free from dirt, dust, paint, oil, grease, rust, and the other foreign materials. And cleans with the cleaner. The Cleaner is uses to clean the surface of welding joints and the connections of member. The specimen to test cleans for applying of the Penetrant in the welding joints.

2. Drying After Cleaning

After cleaning, the member allows to dry. This makes to form a dry and a clean surface for the testing. This takes three to five minutes depending on the condition of the site. And size of the material to test. This cleaning makes, if any residue of liquid presents on the member, it blocks the passing of the penetrant. This drying process carries with the help of hot air driers, air blowers, etc.

3. Penetrant Application

The Penetrant applies to the dry surface. This carries with brushing or spraying. For better, accurate and quick results, the spraying operations carries out.

It sprays exactly on the surface of members. And sprays exactly on the welding connections for examining of the flaws.

4. Penetrant Dwell

The penetrant remains on the surface for a sufficient time to passes into the defects. This dwell time is the total time that the penetrant is in contact with the surface. This varies depends upon the application method, the type of materials, etc,. The normal dwell time is three to five minutes. This depends on the size of materials, the length of welding joints.

5. Excess Penetrant Removal

After sufficient penetration, the excess penetrant all around the surface of material wipes off. And cleans in all the welding joints. This cleaning carries out with a dry clothes and clean wipers.

6. Drying

After removal of the excess penetrant, it allows to dry in normal temperature. No other drying methods like, drying with hot air driers, air blowers, etc requires. This penetrant allows to remain on the member for five to ten minutes. It depending on the size of materials and the length of welding joints. This makes the penetrant sink into the cracks, pores, holes, etc. This depends on the size of the welding joints and connections.

7. Developer Application

The Developer is a thin layer white in colour. It applies quickly on to the surface. And the welding joints, to examine on the truss members. This carries out with the spraying. The complete area of penetrant covers with spraying the Developer.

This application of developer carries out within one to two minutes after drying of the penetrant. This developer available in various forms like, dusting, dipping, spraying.

8. Indication Development

The developer allows to remain on the surface for a sufficient time period. This development time is a minimum of ten minutes. And the maximum time periods take place depending on tight cracks.

9. Inspection

The Inspections performs after a minimum time period of ten minutes. And under necessary lighting to detect the indications from the defects, flaws.

10. Evaluation

The discontinuities in welding joints identifies. It is clearly visible on to the surface welding joints. And the cracks, fractures, pinholes, porosity, potholes, evaluates.

abbu riyaz

Recent Posts

Cargo Hangars in Airport

Cargo Hangars in Airport is discuss in this post. These are large square and rectangular…

3 months ago

Military Hangars

Military Hangars is discuss in this post. These are the large, secure structures use for…

4 months ago

Maintenance Hangars

Maintenance Hangars in Airport is discuss in this post. These are the large square and…

4 months ago

Box Hangars in Airport

Box Hangars in Airport is discuss in this post. These are large square and rectangular…

7 months ago

T Hangars in Airport

T Hangars in Airport is discuss in this post. This is one of the types…

9 months ago

Types of Airport Hangars

There are many types of Airport Hangars and it is discuss in this post. These…

1 year ago