Healthways Scuba Regulator Exhaust Diaphragm & Duckbill
Nov 30, 2019 17:41:55 GMT -8
spirou and Jim Perdway like this
Post by SeaRat on Nov 30, 2019 17:41:55 GMT -8
Let's discuss a bit about the original Healthways Scuba exhaust. Helathways knew it needed to get around the U.S. Divers Company duckbill-style exhaust, and so it had to invent a new exhaust. What they did was to put the exhaust on the top box, about 0.75 inches above the diaphragm. Then they used this increased water pressure from the diaphragm to close a second exhaust diaphragm that sealed the exhaust hose. Here's a diagram of the difference:
SCUBA vs Aquamaster001 by John Ratliff, on Flickr
Without the diaphragm, here's what the Healthways exhaust looks like:
IMG_0779 by John Ratliff, on Flickr
This is a photo of the Healthways exhaust tube within the exhaust diaphragm, which covers this area normally.
IMG_0778 by John Ratliff, on Flickr
This is what the Healthways exhaust diaphragm looks like when in place, and cleaned up.
Healthways Scuba Exhaust Calcs by John Ratliff, on Flickr
Here's a calculation I made of the water pressure on the exhaust diaphragm when the regulator housing is horizontal to the surface of the water, and face-down.
Unfortunately, there is a difference in the other direction when the diver starts a surface dive, and becomes vertical. In this position, without a small duckbill inside the exhaust tube, there is water intrusion into the hose. I've dived the Healthways Scuba without this duckbill, and it works well once the hose is cleared after a surface dive; actually it works better than the USD equivalent duckbill, with a very light exhalation pressure needed to exhaust the air. But Healthways always had the small duckbill (visible within the tube in the photo above) in their Scuba regulators (first generation). Here's a photo of the exhaust duckbill Healthways included:
IMG_2688 by John Ratliff, on Flickr
Healthways Scuba Hybrid5 by John Ratliff, on Flickr
There is a secondary exhaust set of holes in some Healthawys Scuba regulators, in case that exhaust diaphragm sticks to the metal tube edges. Those need to be covered with a rubber band. (By the way, do you see the difference between this regulator's internals and the original Healthways Scuba? That's right, this is a hybrid Scuba, with a Gold Label innerds on the original box.)
Healthways Scuba Hybrid3 by John Ratliff, on Flickr
In case the diaphragm is unusable (holes, or so stiff it no longer seals), a new one can be made from the thin nitril or latex material from gloves. It needs to be thin, and I've now gone to the blue nitril gloves that doctors and nurses use (I got several from a doc at my last appointment, as they simply throw them away when they've been used for an exam). I now use two layers, with a layer of Shoe-Goo between and the wire clamp over the top. This makes a very secured and water-tight diaphragm to replace the original one. The latex material will not stand up more than about one season, so be aware of its limitations. The nitril material is much more durable, and still thin and flexible.
John
SCUBA vs Aquamaster001 by John Ratliff, on Flickr
Without the diaphragm, here's what the Healthways exhaust looks like:
IMG_0779 by John Ratliff, on Flickr
This is a photo of the Healthways exhaust tube within the exhaust diaphragm, which covers this area normally.
IMG_0778 by John Ratliff, on Flickr
This is what the Healthways exhaust diaphragm looks like when in place, and cleaned up.
Healthways Scuba Exhaust Calcs by John Ratliff, on Flickr
Here's a calculation I made of the water pressure on the exhaust diaphragm when the regulator housing is horizontal to the surface of the water, and face-down.
Unfortunately, there is a difference in the other direction when the diver starts a surface dive, and becomes vertical. In this position, without a small duckbill inside the exhaust tube, there is water intrusion into the hose. I've dived the Healthways Scuba without this duckbill, and it works well once the hose is cleared after a surface dive; actually it works better than the USD equivalent duckbill, with a very light exhalation pressure needed to exhaust the air. But Healthways always had the small duckbill (visible within the tube in the photo above) in their Scuba regulators (first generation). Here's a photo of the exhaust duckbill Healthways included:
IMG_2688 by John Ratliff, on Flickr
Healthways Scuba Hybrid5 by John Ratliff, on Flickr
There is a secondary exhaust set of holes in some Healthawys Scuba regulators, in case that exhaust diaphragm sticks to the metal tube edges. Those need to be covered with a rubber band. (By the way, do you see the difference between this regulator's internals and the original Healthways Scuba? That's right, this is a hybrid Scuba, with a Gold Label innerds on the original box.)
Healthways Scuba Hybrid3 by John Ratliff, on Flickr
In case the diaphragm is unusable (holes, or so stiff it no longer seals), a new one can be made from the thin nitril or latex material from gloves. It needs to be thin, and I've now gone to the blue nitril gloves that doctors and nurses use (I got several from a doc at my last appointment, as they simply throw them away when they've been used for an exam). I now use two layers, with a layer of Shoe-Goo between and the wire clamp over the top. This makes a very secured and water-tight diaphragm to replace the original one. The latex material will not stand up more than about one season, so be aware of its limitations. The nitril material is much more durable, and still thin and flexible.
John