Flex Conduits, Venting & Air Flow

Internal Visiport Venting
Visiport's patented design incorporates the ability to vent ambient or "clean" air from outside the machine cabin to prevent internal fogging of the Visiport. The most common method of providing this air flow is throught the use of flex conduit, which is a stainless steel wire braid over a PTFE (Teflon) tubing material. Alternatively, T2K also provides PUR (polyurethane) tubing as an alternative conduit material.

Venting and Air Flow
Improper installation or excessively long lengths of conduit can block or restrict air flow to the unit. This can allow the Visiport spin window to fog up and can possibly lead to electrical and/or mechanical malfunctions. The slight pumping action caused by disc rotation pulls ambient outside air into the unit. When this is closed off, the disc may draw coolant from inside the labyrinth seal instead, leading to fogging or condensation problems inside the unit.

Restriction of air flow can be caused by (a) over-tightening the fittings, (b) accidentally putting a crimp in the conduit or tubing, (c) inappropriate placement of silicone sealant during installations, or (d) excessively long conduit length that restrict air flow.

Please note that adequate air flow to the unit through installed flex conduit is necessary for the unit to function properly. The flex conduit protects the wiring harness between the Visiport unit and the external bulkhead assembly on/off switch and/or motor electronics, but it is air flow that is the primary purpose behind the use of the flex conduit, PUR tubing, and STK-Steel Tubing Kit (for discontinued Visiport VP210, VP215 and VP220 models) sold with the product.

If your unit experiences this problem, please check to see that the conduit is not blocked. If you suspect that coolant has been drawn into the conduit itself, please disconnect and drain the collected coolant, as coolant that settles at the low point of the conduit will prevent any air flow from passing into the unit. Once you have ensured that the conduit is clear, check that the conduit does not have any kinks that would restrict air flow.

If the span distance between the installation point on the window and the bulkhead point is very long (3+ meters for PUR and 5+ meters for flex conduit), consider relocating the bulkhead point closer to the unit to minimize the conduit length as much as possible. This will greatly aid the ability of the unit to pull in ambient air. Where this is not possible, consider adding a second length of tubing dedicated to providing air to the unit. The Visport unit is equipped with more than one connection point, making this easily possible by replacing the plug fitting with the appropriate connector fitting for an additional flex conduit or PUR tubing length.

Custom OEM Wiring Harness / Tubing Designs
Customers incorporating their own tubing scheme to route the wiring harness between the Visiport and the external bulkhead assembly or the machine tool's electrical cabinet should note that it is extremely important to ensure adequate air flow is accommodated in their custom tubing designs.

If aesthetics or integration concerns demand a customized routing scheme, air flow considerations cannot be overemphasized. Due to the necessity to prevent fogging and internal moisture problems that may cause premature product failure, T2K can easily supply flex conduit for new or currently in service Visiport units. In addition, T2K is happy to provide technical support to customers who require custom installations. Contact T2K for details.