MPEX-00-ENG-002-A3 (1) (1).pdf

Vacuum Handbook Appendix 3:

Knife Edge Flange Bolt Torque and Tightening

Requirements

MPEX-00-ENG-002-A3

MATERIAL PLASMA EXPOSURE EXPERIMENT

(MPEX)

Prepared by

OAK RIDGE NATIONAL LABORATORY

Oak Ridge, TN 37831-6283

Managed by

UT-BATTELLE, LLC

For the

US DEPARTMENT OF ENERGY

under contract DE-AC05-00OR22725

This report was prepared as an account of work sponsored by an agency of the

United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights.

Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United

States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.

Knife Edge Flange Bolt Torque and Tightening Requirements for the

Material Plasma Exposure Experiment Project

MPEX-00-ENG-002-A3

Author(s):

Jeffrey Ulreich, Lead Engineer, MPEX VS Vacuum Vessels Date

Reviewer(s):

Aftab Hussain, MPEX Lead Engineer Date

Approver(s):

Adam M. Aaron, CAM, Vacuum Systems Date

Distribution:

Mike Kaufman, Plasma Source and Heating CAM

Ted Boyd, Lead Engineer for PMI and TEC

Knife Edge Bolt Torque and Tightening Requirements for the

Material Plasma Exposure Experiment Project

MPEX-00-ENG-002-A3

Revision History

Revision Date DESCRIPTION OF CHANGE

REVISION TYPE

Major Minor

0 April 28, 2023 Initial Issue ☐ ☐

TABLE OF CONTENTS

1 BOLT TORQUE

2 BOLT TIGHTENING PROCEDURE

3 BOLT TIGHTENING PATTERNS

TABLE OF FIGURES

Figure A 3-1. 6 bolt flange tightening pattern

Figure A 3-2. 8 bolt flange tightening pattern

Figure A 3-3. 16 bolt flange tightening pattern

Figure A 3-4. 24 bolt flange tightening pattern

1 BOLT TORQUE

Bolt tightening torques and patterns are necessary to assure a leak tight vacuum seal on Conflat

(CF) flanges. All fasteners and threads will be precision cleaned. This requires that lubrication is added to the threads to prevent galling. The following lubricants may be used on fasteners for

MPEX Device CF flanges.

1. Apiezon H – preferred lubricant for temperatures up to 240 C

2. Dry Lubricants for temperatures exceeding 240 C

a. Graphite

b. MoS2

c. WS2

Table 1-1 contains the specifications for bolt tightening torques by bolt size for Knife Edge /

ConFlat Flanges. The table is for lubricated stainless-steel fasteners to stainless steel threads.

Table 1-1

Knife Edge Bolt Tightening Torque for Lubricated Stainless-Steel Fasteners, Flanges, and Threads Bolt Size (UNF) Flange Size Recommended Torque (ft lb) Maximum Torque (ft lb)

#8-32 1.33 CF 1.65 7

1/4/2028 2.75 CF 7.83 12

5/16/2024 4.5 CF to 10 CF 11.83 15

3/8/2024 13.25 CF to 16 CF 11.83 28.75

2 BOLT TIGHTENING PROCEDURE

1. Flanges should be aligned with gaskets and bolts finger tight.

2. Prior to tightening the bolts any further, it should be verified that the gasket is seated.

3. From finger tight, the bolts should be tightened ½ turn using the appropriate Bolt

Tightening Patterns from section 3 of this document.

4. As the flange seats and gets tight, bolt tightening should be reduced to ¼ turn at a time

5. Flanges should then be tightened ¼ turn at a time, using the provided Bolt Tightening

Patterns, until the recommended torque is achieved.

6. A leak check shall then be performed. If a leak is found, bolts should be tightened not more than ¼ turn at a time and not to exceed the maximum torque from Table A3-1.

7. If the maximum torque is reached and the connection still leaks, the bolts should be removed and the knife edges and gasket should be inspected for contamination and damage.

NOTE: For non-stainless-steel threads, the design engineer must evaluate thread pullout forces and bolt torque requirements for assuring a leak tight vacuum seal.

3 BOLT TIGHTENING PATTERNS

The following 4 figures show bolt tightening patterns to be used when tightening knife edge flanges on the MPEX project. For flange sizes not listed, please consult with the MPEX Vacuum

Team.

Figure A 3-1. 6 bolt flange tightening pattern

Figure A 3-2. 8 bolt flange tightening pattern

Figure A 3-3. 16 bolt flange tightening pattern

Figure A 3-4. 24 bolt flange tightening pattern