24-09-2014, 04:45 PM
Abstract To reduce leakage in valves Valve leakage refers to flow through a valve which is set in the \'off\' state. I.e. flow through valve when valve is closed. TYPES OF LEAKAGE IN VALVES 1. Seat leak 2. Ring leak 3. Gasket leak 4. Back Seat leak 5. Plug leak 6. Body porosity. REASONS FOR DISCREPENCIES: 1. Workers do not work properly. 2. Learner boys do most of the work. 3. Workers do not use measuring gauges properly. 4. Due to uneven tightening done by worker. 5. Workers do not devote proper time in manufacturing. 6. Lack in supervision. 7. Most of the valve is leaked due lack of lapping. SUGGESTIONS � Remedies to reduce Seat Leakage 1. Need to do proper lapping for proper time. As we have maximum leakage due to this factor. What we need to Flap during/after lapping follows:- I. Proper gauge to Flap alignment. II. There should not be any mark of crack after lapping. III. There should not be any mark of indent after lapping. IV. Proper abrasive paste / paper should be applied so that it should lapped properly. � Remedies to red
PROJECT REPORT
(B.TECH)
Name of company/Organization Bharat Heavy Electricals Limited (BHEL)
Address Goindwal Sahib (Amritsar)
Name of Project Done To reduce leakage in valve
Period of Training from 11 June 2013 to 10 December 2013
TRAINING MANAGER/GUIDE SUBMITTED BY
Signature: Name: Manish Kumar
Name: Sh. Harpreet Rai Branch: ME.
Designation: Sr. Manager Univ. Roll No: 100761133058
Department: Production Email: manishkumar1107[at]gmail.com
Seal:
CONTENT
S.no. Text Page No.
1. To reduce leakage in valve 3
2. Types of leakage found in valve 3
3. Causes of leakage in valves 3-5
3.1 Causes of seat leak 3
3.2 Causes of ring leak 4
3.3 Causes of gasket leak 4
3.4 Causes of back seat leak 4
3.5 Causes Plug leak 5
3.6 Causes of Body porosity 5
4. Test and inspection items 5-11
4.1 Material inspection 6
4.2 Non destructive examination 6
4.3 Visual inspection 6-7
4.4 Hydrotesting 7-11
5. Method of applying the test pressure for each types of valve 11
6. Acceptance criteria 11-12
7. Low pressure seat and seat seal weld procedure 12
8. Observations 13
9. Types of leakage found 13-14
10. Percentage of leakage found 14
11. Reasons for discrepancies 15
12. Suggestions 15-18
PROJECT REPORT
1 To reduce leakage in valves
Valve leakage refers to flow through a valve which is set in the \'off\' state. I.e. flow through valve when valve is closed.
2. TYPES OF LEAKAGE FOUND IN VALVES
1. Seat leak
2. Ring leak
3. Gasket leak
4. Back Seat leak
5. Plug leak
6. Body porosity.
3. Causes of leakage in valves
3.1 Causes of seat leak
1. Improper lapping
2. Improper matching of wedge and seat
Fig.1-Crack on Wedge
3.2 Causes of ring leak
1. Due to wrong welding
2. Due to porosity in seat fixing area
3. Due to thread damage
4. Wrong welding technique
3.3 Causes of gasket leak
1. Due to improper tightening of studs
2. Due to improper fitting of gasket
3.4 Causes of Back seat leak
1. Wrong welding
2. Improper chamfer on back seat
3. Back seat crack
Fig.2-Crack in Bonnet
4. Pin hole in crack
5. Improper chamfer on studs
6. Improper lapping in back seat
3.5 Causes of plug leak
1.