IP/HF port on bottom of mk25?

[novasquid]

this may be a stupid noob question, but what's the purpose of the port circled in red below? is that what scubapro calls an "Intermediate pressure (IP) and High Flow (HF)" port? if so, what's it used for?

 

[Scared Silly]

When ever a gas or liquid makes a turn there is friction which slows the flow. The port in question is a straight shot (i.e. inline) with the piston which lets gas in from the HP chamber. As such, there is little friction to slow the flow. So in theory it has a higher flow rate than those ports on the sides where the gas makes a bend. Key word here is in theory - then there is practical matter. The increase in flow in minimal over the other ports so the amount of gas difference one would get at their second stage is minimal. Also some pistons actually have a diffuser at the end which creates a turbulent flow in the LP chamber.

IMHO it is much to do about nothing and is all marketing.

 

[redacted]

Most importantly, it is the port that is best used with a long primary hose configuration.

 

[novasquid]

Most importantly, it is the port that is best used with a long primary hose configuration.

can you explain this a little more? i assume you're talking about a 7' hose that wraps around your body? is it the best port for a long primary hose because of the "HF" designation or because of it's location (bottom vs side of regulator)?

 

[mala]

its an extra option for keeping your hoses nice and tidy.

a-clamp?
yuk.

 

[redacted]

can you explain this a little more? i assume you're talking about a 7' hose that wraps around your body? is it the best port for a long primary hose because of the "HF" designation or because of it's location (bottom vs side of regulator)?

actually, many long hose rigs will route best from that port. With the long hose on that port and the 1st staged on the tank pointing about 20 degrees off of vertical, the long hose is headed down the divers side where you want it. And an alternate off one side port and the LPI hose off an opposite side port are also headed in the direction you want them. A 7' hose is one option. I only dive open water and don't need 7' but my 5+ feet hoses use the same initial routing but loop up under my arm and across my chest. I adopted this rig when I just got tired of the standard hose which looped out and away from me kept snagging on stuff (coral, tree limbs). My wife uses a 40" hose which also come off that end port and under her right arm. She did not like the loop across her chest and behind her neck so the 40 inch hose loops under her right arm and back up to a 90 degree fitting on her primary. In all cases, the hoses stay close to the body and are not hanging out looking for something to catch on.

 

[beanojones]

In sidemount setups, that so called '5th port' becomes crucial to routing the inflator hose in many setups. I can fake my way around it, but I prefer having the fifth port.

Some examples:
Apeks Sidemount Regulator Package

Hogarthian Configuration Regulator Packages - Dive Gear Express

 

[herman]

IP is a term used in regulators to descripe the pressure that the first stage reduces tank pressure to, all of the LP ports/hoses are at IP. The flow rate information of the particular port that you show is 99.999% sales BS. While it is true that IF and it's a big IF you have an air supply that is capable of flowing more gas than the regulator itself (scuba tanks can not) and you remove the plugs in the reg one by one and measure the flow of each one, that port will likely flow slightly more than the others. However, the second stage is not capable of flowing anywhere near the amount of gas that any of the ports can supply much less that one so the second stage becomes the limiting factor when it's installed. Add to that the fact than no diver can breath anywhere near the max flow of the second stage it becomes even less improtant. It's like claiming one car can go 175 mph and another one can go 150 mph but both have speed controls that limit them to 100 mph and are driven on roads with a 35 mph speed limit. Sure one can go faster than the other but both are limited to 100 mph and then driven on a 35mph road.....is it worth the extra money just to be able to claim your car is the fastest? Same thing with this reg, nice reg but many less expensive ones will do the same job.

 

[chrpai]

As it's already been said, I just like the hose routing on that port for my long hose. Though for me it's on a Hog D1.

I had an MK20 and now a BP2 for a pony bottle and in that use the port doesn't route cleanly.

 

[Lorenzoid]

As it's already been said, I just like the hose routing on that port for my long hose. Though for me it's on a Hog D1.

I had an MK20 and now a BP2 for a pony bottle and in that use the port doesn't route cleanly.

Dive Gear Express configured my new HOG rig with the LP inflator on that central port. The primary and alternate hoses are on side ports. It seemed weird to me, so I changed the LP inflator to another side port. However, what you describe--putting the long hose on the central port--makes a LOT of sense to me, as I found my (5-foot) long hose routing to be uncomfortable. The way it's set up now, when I have donned my gear, the long (primary) hose and short (alternate) hoses tend to interfere or rub against each other.