This is a pair of sealing flange with the water cooling jacket valve for OD 100- 102 mm ( 4" ) diameter processing tube. If you cannot use a ceramic block in two ends of the tube, you must use the water cooling jacket to keep the flange cool (otherwise silicone o-ring may get damaged)SPECIFICATIONS Features Made of Stainless Steel with double high-temperature silicon O-rings on the flange. Stainless steel needle valve with 1/4" pipe adapter. The assembly kit will seal both ends of a 100-102 mm diameter ceramic and quartz tube. A vacuum gauge is installed on one side of the flange. Max. The furnace working temperature is 1150°C without thermal block if the tube furnace is installed with this water cold flange. You may choose the left side, the right side, and the full set of the flange at the product option bar Please always use a recirculating water chiller ( see related product below ) to save water. Vacuum level 10E-2 torr by a mechanical pump 10E-5 torr by a small turbopump and 10-6 torr by hi-speed turbopump Options Please click here to order digital vacuum gauge for precision vacuum control up to 10-4 torr For CVD application, please choose anti-corrosive vacuum gauge ( click pic below left 2 ) You can choose the various end of fitting as options ( click here to order separately ) You may click here order a flowmeter to control gas flowing You may order flange support to avoid tube turning ( picture below right) Warning Must put a refractory tube block in front of the flange (see picture below) to avoid heat radiation melt silicone O-ring. You may order a ceramic block in related products. Please do not over tighten the three hex screws on the flanges to avoid overpressure incidents. The recommended torque is 35~40 inch-lbs. For liability considerations, MTI does not recommend or endorse the use of any toxic, flammable or corrosive gases with our flange assemblies. Please contact us with any concerns. Options Click here to choose flange for tube from 1" to 11" Vacuum Pump & High Vacuum Station