Every part in your operator manual has a QR code that lands on its exact product page.

Sight spools and the 2 inch windows that go in them, so an operator can watch a column instead of guessing at it.

• The 4 inch and 6 inch spools are sold bare, with no sight glass fitted. Budget for the spool, two windows, two 2 inch clamps and two 2 inch gaskets to finish the build.
• Every 6 inch spool comes with a 1/4 inch bore-through for a thermocouple. The probe is sold separately, in Thermocouple Parts.
• Both 2 inch windows are borosilicate with a stainless frame, certified to 300 psi and -40 to 572 F (-40 to 300 C).
• On a system pulling deep vacuum, the 2 inch sight glass is usually the limiting component, not the vessel. Worth knowing before you size the rest of the stack.
• Spools are fabricated in Bend, Oregon in 4 inch and 6 inch. We do not make an 8 inch spool.

Clamp and gasket pressure ratings are tabulated in Tri Clamp Pressure Ratings.