Line plugging is a method of isolating or temporarily blocking-in a section of pressurized line for purposes of alteration or maintenance, This is done without shutting down the system and without loss of product. If flow must be maintained, a temporary or permanent bypass can be installed around the work section (see illustration at end of page).

Topaz is currently equipped for the following:

A.	Low pressure plugging 1" through 48". 60 PSIG Max, pressure @ 100° F. 250° F. Max. temperature @ lower pressures.
B.	High Pressure plugging: 2" through 16". 900 PSIG Max. pressure @ 100° F. 350°F. Max. temperature @ lower pressures.

In addition to extreme pressure and temperature, Topaz is experienced with and highly qualified for work involving particularly volatile, corrosive, and toxic products.

Fittings and valves:
Topaz maintains a large inventory of completion type fittings for use in low and high-pressure line plugging applications. Available from stock in popular sizes and flange ratings, these specialty fittings enable us to work through Topaz temporary valves during the plugging operation. When the work is completed, we secure a metal plug in the fitting just below our temporary valve. The temporary valve is then depressured and removed, and the completion fitting is blinded off.

When desired, plugging work can also be performed through permanent valves and standard hot tap fittings. Contact Topaz for required bore diameters and overall fitting and valve dimensions prior to welding.

Information we require for line plugging:

1. Nominal size of the line.
2. Single or Dual (see below)
3. Material and wall thickness or schedule of the line.
4. Product in the line.
5. Operating pressure and temperature.
6. Maximum pressure and temperature while plugged.
7. Blowdown and equalization provisions.
8. Size of bypass, if required.
9. Scope of alteration or maintenance while line is plugged.
10. Orientation of the line and preferred fitting orientation.