| Valve as found: |
Original Info: |
Actuator / New Info: |
| Manufacture |
Republic Flow Meters |
Limitorque Gear box |
| Size |
8"x 8"x 8" |
Model: L120 - Size: 420 |
| Type |
Globe |
Solid stem / disc assembly, post-
guided, control valve. Single seat |
| Pressure |
1500 Lb, Pressure Class |
|
| Body Material |
WC6, Steel (1-1/4 % Chr.) |
|
| Fig.# |
DRW# 5000-32-8 |
|
| Seat Material |
Stellite #6 (per provided drawing) |
309L-SS / Stellite-#21 Overlay |
| Stem Material |
CR-13 |
Stem Diam. 2" Acme 4-TPI SL LH |
| Disc Material |
CR-13 (repaired in past) |
309L-SS / Stellite-#21 Overlay |
| End Connection |
Butt-weld Schedule - Not Shown |
Likely Schedule - 160 |
| Electrical Disconnect |
Yes |
|
| Insulation |
No |
Hot Work Permit Required For Heating Or Welding |
| Scaffolding |
No |
|
| Gasket Info (2) Required upper and lower bonnet |
Style: flat steel |
7.250" x 8.437" x Th. 1/16" Manufactured by TFSG |
| Stem Packing Information (style & cross section) |
Found 14 Rings of Rope Packing |
Replacement - Garlock 1303 Cross-section 1/2" x 1/2" 5 Rings. |
| Problems found: |
| |
| Seats: |
 | Evident leak through past seating surfaces, possibly causing flow control problems for the adjacent regulating valve. (Debris was found in upper and lower guide bushing of valve body.) |
| | Severe cuts found on Disc and Seating Surfaces. |
| |
| Stem: |
| | Minor pitting in packing area. |
| | Upper Guide Post had severe gouges and galding caused by fractured weld of adapter plate at weld joint of bonnet / adapter plate. (This two piece construction was not shown on station supplied drawing.) |
| |
| Bonnet: |
| | Bonnet / Adapter Plate weld joint fractured approximately 60% of the total circumference causing actuator adapting plate to bend approximately .140". Possibility of incorrect torque setting on Limitorque actuator. |
| | Upper Guide Bushing mirrored damage from upper guide post of stem. |
| | Depth of Packing Box on Bonnet is unacceptable but common for this vintage of valve. Appearance of possible packing leak. Depth adjustment required. |
| |
| Gear Operator/Actuator: |
| | Stem - drive nut shows minor wear on acme threads. However, acceptable for continued use. |
| |
| Body: |
| | Acceptable. (No evidence of cavitation or Body Damage.) |
| Corrective Action: |
| |
| Seats: |
| | Removed old seat ring from valve body, manufactured and installed new seat ring. |
| | Removed approximately .400" total from diameter of disc by means of machining. |
| | Applied .200" of 309SS re-machined. |
| | Applied .200" Stellite21 hard-surfaced material. Finish machined to proper configuration and dimensions. |
| |
| Stem: |
| | Check the T.I.R., found to be acceptable (.002" Run Out) |
| | Polished the packing area and lower post guide surfaces. |
| | Weld repair were made on upper guide post where gaulding had occurred. Weld repairs were made with 309SS; Upper guide post was then machined and polished to finished diameter of 2.604". |
| |
| Bonnet: |
| | Separated adapter plate and upper guide bushing from bonnet. |
| | Re-Machined both sides of adapter plate for a 98% clean-up. |
| | Machined away remnants of old weld material from adapter plate leaving area for new weld material to be applied during construction. |
| | Fit and re-assembled adapter plate and valve bonnet applying 3 passes of 3/32" 8018 around circumference of point of attachment. |
| | Manufactured and incorporated 4 triangular gussets equally spaced 90° apart for additional strength as part of the bonnet / adapter plate reconstruction. |
| | Machined the nut shoulder surfaces to remove gaulding marks from bonnet nuts (97% Clean-up) |
| | Manufactured the new upper guide bushing from A105 Carbon steel pipe with 309SS / Stellite21 overlay on contact surface. Installation was .002 pressed fit with 4 tack welds. |
| | Manufactured new packing spacer to allow for proper compression of 5 ring packing set. |
| | New flat steel gaskets were manufactured to replace upper and lower bonnet gaskets. |
| |
| Body: |
| | Body was thoroughly cleaned; Valve was re-assembled and checked for smooth operation and proper alignment. |
| | After unit was brought up on load TFSG tech hot torqued bonnet bolts and packing in conjunction with a visual inspection for leaks or problems. None found. |
| |
| Recommendations: |
| | Factory maintenance recommendations for Limitorque, motor operators are mostly based on: number of cycles, temperature, severity of service, torque, or limit settings and other sizing characteristics. |
| | It is TFSG recommendation that routine maintenance be performed on this motor operator at earliest opportunity. |
| | Although the valve was hot torqued after start-up, periodic packing adjustments and visual inspections are recommended every 3 months. This can be done by station maintenance personnel. |
