D.E. Multiport Valve Sight Glass Question

[Scoop]

I have a D.E. Filter with a Pentair 2" Multiport Valve P/N 261152 .

I've been looking at replacement Sight Glass part information and I'm curious about a particular Sight Glass. The Pentair P/N is 272550 "Sight Glass w/Vacuum Projector".

My original Sight Glass is an OEM "Praher" P/N E-17-S1. Here's the picture:





Here's the picture of the Pentair 272550 Sight Glass:



I'm assuming that the "vacuum projector" is the circled area. What is the vacuum projector? What does it do?

 

[JasonLion]

That includes a valve which is designed to let air into the system if there is a slight vacuum, but shouldn't let anything come out through the valve. It can be useful if your waste line doesn't fully drain after use. By letting air in, it allows the waste line to drain in the rare cases where it wouldn't do so on it's own. However, it is also another thing that could break, and slightly reduces the visibility through the sight glass.

 

[Scoop]

for the info. I'll probably stay with an original replacement part.

 

[Garrobo]

yeah, more **** that can break.....or maintain!!!!!
I don't believe that this is an upgrade (in performance) to the older design either.

If it not broke, then don't fix it.

That includes a valve which is designed to let air into the system if there is a slight vacuum, but shouldn't let anything come out through the valve. It can be useful if your waste line doesn't fully drain after use. By letting air in, it allows the waste line to drain in the rare cases where it wouldn't do so on it's own. However, it is also another thing that could break, and slightly reduces the visibility through the sight glass.

 

[Scoop]

yeah, more **** that can break.....or maintain!!!!!
I don't believe that this is an upgrade (in performance) to the older design either.

If it not broke, then don't fix it.