Issue & Importance
A Canadian methanol producer was using a line blocking system designed when the plant was originally built in the 1970s. At least two workers were required to spread the pipe at a flange in order to put the blocking system in place.
When the reformer tripped, which happened three times a year, it took approximately eight hours for a crew of two to four workers to isolate all six critical lines. Each hour of lost production time cost the plant roughly $20K.
The piping and welding manager knew that there had to be a better solution and approached Armour Valve for advice. Our partner SchuF offers a Cam-Set® Line Blind with advantages over traditional blocking which we presented for consideration.
Solution
After extensive research and evaluation, the piping and welding manager decided to install six SchuF Cam-Sets® on lines ranging from 1” to 12” and pressure rating from ANSI 150 to ANSI 900 class.
SchuF designs and manufactures its Cam-Set® Line Blinds with efficiency and safety as top priorities. Unlike traditional line blinds, a single worker without the use of special tools or equipment can operate a 10” or smaller SchuF Cam-Set® Line Blind. In sizes above 10”, Cam-Sets® are equipped with a counterweight option to facilitate quick blinding.
In addition, all of the bolts are tack welded and cannot be unintentionally removed or loosened. With no bolts to remove or loosen, the plant was able to achieve absolute positive safe shut-off of all six lines in less than 15 minutes. The overall process took approximately 1 hour including travel between lines.
Impact
The methanol producer’s main priority was safety, followed closely by cost savings. The SchuF Cam-Set® Line Blind ensures absolute isolation. If the blind were to leak, it would leak to atmosphere and not downstream where people are working. Fewer workers were required to isolate the lines and the plant benefitted from savings on labour hours and downtime (refer to table below). The facility was able to recoup its investment in the first year, after a single trip of the reformer.
| Savings/Event | Conventional Orifice Plate | SchuF Cam-Set® Line Blind | Savings |
|---|---|---|---|
| Work hours | 8 | 1 | -- |
| # of workers required | 2 to 4 | 1 | -- |
| # of worker hours | 16 to 32 | 1 | 93.7% to 96.8% |
| Lost production due to downtime | $160K | $20K | 87.5% |
