Click to enlarge2.75" OD Conflat Viewport
Includes (1) Annealed Copper Gasket

2-3/4" OD CF Conflat Flange
Ultra High Vacuum (UHV) Series Viewport
Conflat Flange Glass Viewport - VPA Series
Overstock Price

• DN35CF, DN40CF Zero Length View Port
• Kodial Glass (alkali borosilicate 7056)
• 6 Clearance (Thru) Holes
• 0.265" Bolt Hole Diameter
• View Area: 1.49"
• Flange Thickness: 0.5"
• Glass Thickness: 0.12"
• Viewports are Rated for Vacuum NOT Pressure

See Additional Product Usage Warnings Below

Always Use With Glass Conflat Viewports
• Washer With Each Bolt
• Annealed Copper Gasket (1) Supplied With Purchase
275-VPA Compare to: 9110027 CF275-ZLVP-1.505 P102262 VPZL-275 ZV-150

2.75" CF Glass Viewport

275-VPA-OSPrice: $210.00Overstock: $151.20

Click to enlargePurchase Additional Annealed Gaskets
ACG-275 Series - 1 Supplied with Purchase

Click to enlargeALWAYS Use A WASHER With Each Bolt
Thru Hole Bolt Kits

Conflat Flange (CF) Series Viewports
• Optical discs are Kodial Glass (alkali borosilicate 7056)
• Glass to Metal Seal (No Viton Gasket)
• Metal to Metal Weld

Repeated Bakeout Cycles to 350°F
• heating rate should not exceed 2-3° per minute


ALWAYS Use An Annealed Copper Gasket
• LDS Provides 1 With Each New Viewport Purchase

• Annealed Copper Gaskets are NOT the same as our standard Copper Gaskets: (-CG Part Number)

Caution Required When Using Viewports
• Viewports are Rated for Vacuum NOT Pressure

• All viewports are fragile and must be handled and mounted with extreme caution

• NEVER use a viewport that appears to be, or is known to be damaged

• Never scratch the viewing area; a weakened viewport may implode (or explode) under wrong conditions.

• A faulty viewport can cause serious injury

• Make sure the glass chosen has a reasonable transmission at the wavelengths of interest.

• Remember, what is not transmitted may be reflected or absorbed.

Contact LDS Vacuum with any questions:
Phone (407)862-4643 via Fax (407)862-8723 or

LDS Vacuum Products is a 100% woman owned company and
a certified Woman Owned Small Business (WOSB)
The logos and/or trademarks appearing on this page are not owned by or registered to LDS but, rather, designate products sold by LDS, and are owned and/or registered to the manufacturers or suppliers of the products.