BFM® fittings are often used in various applications where they are operating under negative conditions. Typically these applications are in operations where the plants are drying or processing dry powdered type products and need the machinery to be under a slight negative to keep the internals of the buildings clean from leaking dust out of the machinery. In these applications, the clear Seeflex 040E is often the media of choice as operators are able to see the product circulating the plants.
Although it has been proven that the BFM® fittings will run at negative vacuum well in excess of our suggested maximum of 1000mm (40″), it is recommended that you contact us if you intend to run BFM fittings in excess of these parameters. As the Seeflex 040E offers a near 100% seal, care is needed when running a high vacuum if the connector is off center or pulsing at high vacuum. In these circumstances, a polyester (breathable) type connector is recommended, as this reduces the vacuum across the flexible connector as it breathes air.
The BFM® fitting offers a wide range of benefits over a Hose Clamped Connector:
|Aspects||Standard Hose Clamped Flexible Connectors||BFM™ fitting|
|Hygiene||Product building up between the flexible connector and the sidewall of the spigot||No crevices for product to get caught in|
|Sizing||From inaccuracies in measuring onsite through to production, it can be very difficult to get a perfect fit of a hose clamped connector.||Perfect fit every time|
|Fitting||Both the speed and accuracy of fitting hose clamps can vary widely and often clamps are not fitted correctly.||Can only fit in exactly the correct place, i.e. in or out.|
|Explosion||In an overpressure situation hose clamps are normally always the weakest link and give up or let go long before the flexible connector would be due to rupture.||Only seals tighter under high pressures.|
|Standard Size||Current flexible connectors are made any size whatsoever; hence there are thousands of different sizes.||Set standard sizes in 50mm increments helps standardise stock holdings of spare parts.|
|Health & Safety||When using screwdrivers to tighten up hose dips, damage is common to the flexible connector and even the installers hands.||Tool free connector changing; simply snap in with your hands.|
Conditions for Running BFM® Fittings
- BFM® snap cuff must be inserted correctly into the steel spigot. The band should be snapped out fully to the circumference of the spigot and should be flush all the way around, i.e. there should be no kinks in the cuff of the flexible connector. If you are unsure see fitting instructions supplied with the BFM® fitting.
- When spigots are welded onto ductwork, they must be welded onto the plant ductwork at the appropriate distance from each other. Then this will vary from a straight pipe which is recommended to have at least 10mm play, through to an offset gyrating application where the variance could be up to 60mm-+.
- The BFM® fitting can be run with a wide range of different fabrics, as with the connector. It is important that each of these fabrics have a continuous and upper-temperature limit, if you are unsure these limits should be checked before installation.
When installing BFM® fittings in an application that may be under vacuum it is important to make sure that, particularly when using the non-porous Seeflex 040E, you do not exceed the negative vacuum figures as listed in our literature and on the website.
- Although the BFM® fitting has an almost 100% seal, this cannot be guaranteed on all liquids, i.e. there may be leakage from time to time.
- Ensure that the correct flexible connector material is chosen for the application,i.e. temperature, chemical attack, etc. If unsure contact your local distributor for help on choosing the correct material.
- Preventative Maintenance – As it is impossible to estimate the life of any given connector, always inspect the connector daily for any obvious signs of deterioration.
- For applications where there is a possibility for static build up, e.g. wood dust, flour, milk powder etc., we recommend using a static dissipative wire (strip), connecting the two BFM® spigots together.
For more technical details and datasheets, please visit www.bfmfitting.com