Fab-Tech Blog | Corrosive Process Fume Exhaust Duct

PSP® Fume Exhaust Duct Hot Tap Installation: Part 2

Written by Mike Baranski | Apr 4, 2018 8:19:00 PM

Hot Tap Installation Using a Pressurized Glove Box

We all know that change is the only constant. Therefore, it stands to reason that process systems should be designed with adaptability and the eventuality of change in mind. As process intensive facilities grow, there usually comes a time when air-handling and fume exhaust systems need to be expanded or adapted to meet operational demands.

Fortunately, hot tapping with PSP® is a versatile solution that allows users to retro-fit new PSP® components to a variety of host duct systems without costly, time consuming, or disruptive shutdowns to the system.

This instructional demonstrates the relative ease and simplicity with which a hot tap installation can be performed with a zero-leak glove box on PSP® fume exhaust duct.

Please watch our video below for a visual demonstration of the installation procedure, or read on to follow the written steps:

 


Here are the tools required for this procedure:

  • Metal cutting jig saw with the carbide saw blade
  • Electric or pneumatic drill - drill bit 5/16”
  • Permanent marker
  • Center Punch
  • Duct tape
  • Allen Wrench
  • Glove box (required) with pressure plate
  • Torque wrench & socket

Procedure:

1) Position Tap Template

Place the tap template on the duct at the desired location for a duct tap. Position template such that the tab and alignment bolt hole are located at the bottom of the desired location. 

2) Trace Template

Trace the tap hole and the alignment bolt hole onto the duct using a permanent marker. Also mark with a line the approximate horizontal certerline position of the tap on the duct.

3) Punch

Center punch and drill the alignment bolt hole and a starter hole just above the tab for cutting the tap opening. 

4) Cut Tap Opening

Use a metal cutting jig saw to cut the tap opening. Slide the pressure plate over the tap hole and under the cutout as it is being cut to maintain system pressure. 

5) Position Glove Box

Using the horizontal centerline markings from Step 2, position the glove box on the duct over the tap pressure plate and hold in place with duct tape.

6) Position Tap Backing Ring

Lift the plexiglass viewing window and place the backing ring and the alignment bolt inside the glove box and close the viewing window. Insert hands into the gloves and hold the backing ring.

Have a second person slide the pressure plate out of the way. Position the backing ring inside the duct to align with the curvature of the duct.

Also align the bottom bolt hole on the backing ring with the alignment hole on the tab and thread the alignment bolt into the backing ring to temporarily secure the backing ring. Use allen wrench to tighten the bolt.

7) Remove Glove Box

Slide the pressure plate back over the tap opening using the slot at the bottom of the pressure plate to align with the alignment bolt. Remove the glove box from the duct.

8) Position Tap

Slide the tap with attached end cap onto the alignment bolt using the bottom bolt hole on the tap and carefully remove the pressure plate out from underneath.

9) Install Anchor Bolts

Insert ⅜” anchor bolts into the tap mounting holes and thread the bolts into the backing ring inside the duct. Slide a flat washer and lock washer onto each anchor bolt and thread a nut finger tight onto each anchor bolt. Use an allen wrench to remove the alignment bolt and replace with an anchor bolt and hardware.

10) Tighten Bolts

Torque all of the bolts to 36ftlbs to complete the installation. 

11) End of Procedure

 

ADDITIONAL Information

If you are looking to connect to an existing non-PSP® fume exhaust duct system, specialty adapters and joint acceessories are available for this purpose. Fab-Tec's specialty adapters allow the joining of PSP® duct to a wide range of threaded or other flanged piping systems. Adapters are available for male or female NPT threaded pipe, KF flange pipe, and Swagelok® tubing.

If you would like more information about PSP® corrosive fume vent pipe and duct, please feel free to download our general information guide below:

OR

View Our Duct Installation Adapters and Accessories