MEP Exhaust max temperatures (selecting braided flex hose)

[SteveH]

I've realized that I'm going to need some short braided flex hose to attach to MEP003a the exhaust mufflers (this is so I can get the exhaust pipes to a location where I can attach the regular laundry pipes I'll be using). I've discovered these can't be attached directly if the MEP has an ASK fitted. Although it can be done with various adapters and a vertical length of iron 1 1/4" pipe, I'm trying to minimize the risk of vibration cracking the mufflers or manifold so would prefer to have some flex pipe as close as possible to the standard exhaust outlets.

I need something like this http://www.metraflex.com/flexmet_sst.php ; but does anyone know what the max temperatures are on the MEP? (this is only good up to 600'F). The company does higher temperature (1200'F) 'Manifold Bellows', but I've been unable to find details/pricing on those (though I've just sent them a message).

-Steve

 

[Harleyd315]

I check mine with a infared thermometer and remember about 400- 500 degs measured when I point it at the ex pipes. I havent done it in a while so I can't be dead on with my numbers. I have never had a pyrometer in the exhaust system to really know the exact ex temp though.

 

[SteveH]

I check mine with a infared thermometer and remember about 400- 500 degs measured when I point it at the ex pipes. I havent done it in a while so I can't be dead on with my numbers. I have never had a pyrometer in the exhaust system to really know the exact ex temp though.

Thanks. I also have an IR Thermometer, but at the moment it's pretty cool here, and I can't run it under a lot of load. I had read that older diesels were usually at around 400'F (newer ones with the particulate removal 'cats' run a lot hotter - around 1200'F)

Based on your numbers I suspect that 600F rated flex hose isn't good enough, unless you took your numbers at high ambient temperatures/load.

Thanks,

Steve

 

[doghead]

I would plan for up to 1200 F.

where I can attach the regular laundry pipes I'll be using

What's a laundry pipe?

 

[SteveH]

They are stainless steel flexible pipes, around 11-15' long that were used when MEP's were mounted on 'Laundry Trailers'. They have 1 1/4" NPTP thread fittings at each end, so can be fitted to the standard manifold (actually muffler) outlets on the MEPs

However, I think they were really only designed to fit to units without the ASK; to fit them I've used some 1 1/4" adapters and short vertical iron pipes, but I'd prefer to replace those with regular braided flex to minimize the weight/stress/vibration on the original mufflers and manifold. This is for mounting in a shed - in the end I might not even use the laundry pipes (instead go via the braided flex to horizontal pipes to exit the building)

-Steve

 

[Ray70]

Steve, I think your actual EGT could easily reach well in excess of 600F under a heavy load, however this does not mean that the outer exhaust pipe will reach the same temperature because it will dissapate a substantial amount of heat before the flex pipe. Also, looking at the spec sheet I don't see where that pipe is only rated for 600 degrees. It lists a pressure correction factor for temps up to 600 ( because these are pump isolation hoses) but I'm not so sure that the pipe itself is limited to 600. The construction appears the same as an automobile flex pipes (used on most transverse mounted engines) except for a thicker pipe and NPT threads. I think temperature wise you'll be fine with that flex pipe. What have you found price wise for them? If you go to your local muffler shop or auto supply store you can buy universal braided flex pipes of the same construction for about $25 ea. BUT... it will be thinner exhaust pipe and will need to be clamped or welded on, it won't have an NPT thread. A 1 1/2" I.D. flex pipe might just fit over 1 1/4" black iron pipe and be able to attach with a muffler clamp or weld to a section of black iron, if those flex lines you showed are overly expensive. Go to www.hardydiesel.com and look at their super quiet exhaust kits. The flex lines shown in the photo are exactly what I'm talking about except a little bigger diameter than the one you will need.

 

[storeman]

These are laundry unit hoses. I got 4 with my laundry unit and have used three. A couple of SS members had them available a couple of months ago. Angus was one I believe. Really pricey if you were to try to match on the market. I had auto flex pipe but it is tough to attach, too thin and rusts the minute you install it...Still it was about $30 per 5'piece at Advance and more at Napa. These are great!
Jerry

 

[SteveH]

Steve, I think your actual EGT could easily reach well in excess of 600F under a heavy load, however this does not mean that the outer exhaust pipe will reach the same temperature because it will dissapate a substantial amount of heat before the flex pipe. Also, looking at the spec sheet I don't see where that pipe is only rated for 600 degrees. It lists a pressure correction factor for temps up to 600 ( because these are pump isolation hoses) but I'm not so sure that the pipe itself is limited to 600. The construction appears the same as an automobile flex pipes (used on most transverse mounted engines) except for a thicker pipe and NPT threads. I think temperature wise you'll be fine with that flex pipe. What have you found price wise for them? If you go to your local muffler shop or auto supply store you can buy universal braided flex pipes of the same construction for about $25 ea. BUT... it will be thinner exhaust pipe and will need to be clamped or welded on, it won't have an NPT thread. A 1 1/2" I.D. flex pipe might just fit over 1 1/4" black iron pipe and be able to attach with a muffler clamp or weld to a section of black iron, if those flex lines you showed are overly expensive. Go to www.hardydiesel.com and look at their super quiet exhaust kits. The flex lines shown in the photo are exactly what I'm talking about except a little bigger diameter than the one you will need.

I've been looking at all these options....

The automotive flex pipes with 1.75" i/d auto pipe work if you use a short section of 1.75 pipe - this just slips over the 1-1/4" black iron threads, and also fits inside the flex pipe (but needs two welds at each end). Obviously a less expensive solution, but I'm still thinking that it's better to have an 'industrial' quality threaded flex section (better quality pipe, 4 less welds).

I also found the additional info you mentioned re 600'F being the point at which pressure was rated down to 73% of original. They list pressures up to 1200'F (when it's down rated to 40% of original), so like you I think it's OK. I can get that flex, with the NPT ends for $22, but am seriously considering going for 10" (gives greater flexibility) for $43 each.

Once I've worked this out, I'll post some photos. My set up is similar to Storeman's below, except that I have the ASK on the MEP003a, and am ducting the hot air out of the top of the ASK (he's venting to the inside of the building, then (presumably) has an exhaust fan. As a result, my arrangement of exhausts/duct is slightly more complex on top of the unit.

-Steve

 

[SteveH]

View attachment 459432

Jerry,

What's that 'union' on top of the black pipe (connecting to the laundry pipe). Is it some kind of flex joint or isolator? (It looks a lot larger than a regular union)

-Steve

 

[Ray70]

Steve, for $43 the 10" flex pipe with NPT ends is a no-brainer. Much easier to work with , no welding and no adapters to figure out. The longer flex section the better, ones shorter than 8" are hardly "flexible" at all. I can't wait to see some pictures, I'm still deciding what my dual MEP-002A setup should consist of... if I ever get around to doing a permanant installation with all the other projects ( and 2 little kids) taking up all my time!

 

[SteveH]

That's what I thought! Another vendor just quoted me $690 per flex hose (15" long) at the same spec!!! (plus shipping!)

I just ordered the $43 threaded hoses; will report back once I get them and provide details (I suspect that others might find these useful).

-Steve

 

[storeman]

Jerry,

What's that 'union' on top of the black pipe (connecting to the laundry pipe). Is it some kind of flex joint or isolator? (It looks a lot larger than a regular union)

-Steve

Steve,
The half-union on one of the hoses would not mate up. I went to lowes and bought a standard (made in china) galvanized union. Only one they had at the time.

I'll open doors and run exhaust box fans as needed off convenience outlets.
Jerry

 

[Ray70]

$690 for a flex pipe? maybe he was quoting an 1 1/4" flexible explosion proof electrical conduit connector.... to a government agency.... for use on the space station?? I wonder if it was the same guy who recently quoted me $680 for a frequency transducer...

 

[3dAngus]

Yeah Jerry, that was me selling my laundry unit flex pipes. They were used to exhaust the exhaust gases and fumes away from the troops who would climb up the M1061 scaffold to wash their clothes. Why is it when we sell an irreplaceable item we've held for years, we turn right around and need it. LOL

I loved those things. Anyone know where I can get at least one for my new MEP002?

 

[SteveH]

$690 for a flex pipe? maybe he was quoting an 1 1/4" flexible explosion proof electrical conduit connector.... to a government agency.... for use on the space station?? I wonder if it was the same guy who recently quoted me $680 for a frequency transducer...

Yes...I double checked whether I'd put feet instead of inches for one of the measurements....

Just hoping that the ones I've ordered will do the job.

 

[storeman]

Yeah Jerry, that was me selling my laundry unit flex pipes. They were used to exhaust the exhaust gases and fumes away from the troops who would climb up the M1061 scaffold to wash their clothes. Why is it when we sell an irreplaceable item we've held for years, we turn right around and need it. LOL

I loved those things. Anyone know where I can get at least one for my new MEP002?

I have one left but I haven't thought about selling it. They so far outclass what is available, maybe they were some of those $690 items.

 

[dependable]

Has anyone tried the 10 ft aluminum flex tubes? I bought some of these from a member here, but have not tried them yet.

 

[PeterD]

Has anyone tried the 10 ft aluminum flex tubes? I bought some of these from a member here, but have not tried them yet.

aluminum? There is no way that aluminum will withstand the rigors of exhaust service. Like copper it will work harden (accelerated by exhaust heat) and crack.

As to exhaust temperatures, with a diesel engine temp is directly proportional to load. The more load, the higher the temperature. I'd recommend planning on temps in the range of 1200 degrees for a non-turbocharged engine near the exhaust port and slightly lower as you move past the mufflers.

That said, there is some possibility that you could take exhaust flexes used on some cars (such as a Honda I worked on the other day, which had an eight inch flex section) or the flex tube used on some turbo installations (the GM/AM General 6.5 for example) and with some welding you could create what you are looking for.

 

[dependable]

I'm sure a modern automotive flex section could be incorporated into MEP exhaust system to isolate vibrations. I wonder what these aluminum tubes were for, temporary installations?

 

[storeman]

Dependable,
Are the aluminum tubes equipped with female pipe threads on the ends? What diameter flex is it?
Jerry