Heat exchanger raw water connections

[SeaDogAK]

I’m in the process of installing a new heat exchanger on my Westerbeke 6kw genset. Since I didn’t know how old they are, I decided to replace all the coolant and raw water hoses at the same time. I’ve got the HE installed, and all the coolant hoses installed, but when it came time to start connecting raw water hoses, I discovered that the hose bib for the raw water outlet on the new HE is 7/8” but the old hoses (and the new hose I bought for $200 to replace it) is 1” ID. I tried clamping down the 1” hose on the 7/8” bib, but not surprisingly it sprays water everywhere. I talked to the HE manufacturer, and their suggestion was to replace the 1” hose with 7/8”, which would require me to replace all the downstream fittings, and buy new hose since I already bought 1” hose.

I’m thinking the answer is to put a short length of 7/8” hose on the HE, and use a 1” to 7/8” reducer fitting to connect that to the 1 hose. But I haven’t had any luck finding such a fitting.

I found what looks like a silicone reducer, but I’m not sure that’s going to work for salt water at high temperature. (https://hpsperformanceproducts.com/products/hps-22mm-1-inch-silicone-straight-reducer-coupler-reinforced-transition-hose). I was thinking something made of metal (bronze? Stainless?) would be better, but I haven’t been able to find such a thing.

Does anyone have any ideas on how to hook this up?

 

[Mac G]

Is that raw water under pressure?
Whereas an official bronze fitting might be the best option I might try beefing up the diameter of that 7/8" barb to accept a 1" hose by either slipping on a short section of this walled hose or wrapping it multiple times with blue monster tape. You only need to make up 1/16" of an inch all around, correct?
Can see that simply cranking down on your hose clamp would not work, but beefing up the diameter of the fitting first might work if the line is not under substantial pressure.
While some might deem that mickey-mouse, have personally done such things in the past with success.
For example, slip a short section of clear thin plastic water hose on the 7/8" fitting to turn it into 1 inch.

 

[SeaDogAK]

I suppose it’s under some pressure, because it goes up and over a siphon lock about 2-3’ high on its way to the exhaust, and there’s probably some back pressure from the exhaust.

 

[Caballero II]

I’m in the process of installing a new heat exchanger on my Westerbeke 6kw genset. Since I didn’t know how old they are, I decided to replace all the coolant and raw water hoses at the same time. I’ve got the HE installed, and all the coolant hoses installed, but when it came time to start connecting raw water hoses, I discovered that the hose bib for the raw water outlet on the new HE is 7/8” but the old hoses (and the new hose I bought for $200 to replace it) is 1” ID. I tried clamping down the 1” hose on the 7/8” bib, but not surprisingly it sprays water everywhere. I talked to the HE manufacturer, and their suggestion was to replace the 1” hose with 7/8”, which would require me to replace all the downstream fittings, and buy new hose since I already bought 1” hose.

I’m thinking the answer is to put a short length of 7/8” hose on the HE, and use a 1” to 7/8” reducer fitting to connect that to the 1 hose. But I haven’t had any luck finding such a fitting.

I found what looks like a silicone reducer, but I’m not sure that’s going to work for salt water at high temperature. (https://hpsperformanceproducts.com/...ht-reducer-coupler-reinforced-transition-hose). I was thinking something made of metal (bronze? Stainless?) would be better, but I haven’t been able to find such a thing.

Does anyone have any ideas on how to hook this up?

I had this happen. I went back to my provider and had them provide me with a heat exchanger with the originally specified 1" output. Done. There are other providers of heat exchangers out there who will do it. I can provide specifics if needed, but will take time. I wouldn't go thru the pain or reducers, just have the cooler provider give you the right one.

 

[SeaDogAK]

I had this happen. I went back to my provider and had them provide me with a heat exchanger with the originally specified 1" output. Done. There are other providers of heat exchangers out there who will do it. I can provide specifics if needed, but will take time. I wouldn't go thru the pain or reducers, just have the cooler provider give you the right one.

They’re insisting that the OEM Westerbeke has a 7/8 hose, and someone must have modified mine to a 1” at some point. I don’t know about that, I think the prior heat exchanger is the original one, but it’s 30 years old and I’ve only owned it for 2 years. The hose bib on the old heat exchanger is a separate screw-in piece, so it could have been modified at some point. I’m not really inclined to fight that battle.

 

[Caballero II]

They’re insisting that the OEM Westerbeke has a 7/8 hose, and someone must have modified mine to a 1” at some point. I don’t know about that, I think the prior heat exchanger is the original one, but it’s 30 years old and I’ve only owned it for 2 years. The hose bib on the old heat exchanger is a separate screw-in piece, so it could have been modified at some point. I’m not really inclined to fight that battle.

OK, I understand. But they're I think they're BS'ing you. You likely have the original heat exchanger. I will get you my source for Westerbeke on the west coast who made it right, and the source of my back-up exchanger, also on the west coast who will make anything you need in heat exchangers tomorrow. I just went thru this. Hang in and I will try to help you.

 

[SeaDogAK]

I appreciate whatever you can come up with. But I have to say the rescue tape idea has some appeal. I’ve now been messing with this since July, and I need to get this fixed and move on.

 

[Comodave]

On supplyhouse.com I found this adapter. Did a Google for 1” barb fitting to 7/8” barb fitting. It pulled up more but this was the first one. Not sure if this is what you are looking for or not, but maybe?

1" x 7/8" PVC Reducer Insert Coupling (Insert x Insert)

 

[SeaDogAK]

PVC isn’t heat resistant, it starts to melt at 140 F. This is the hot raw water line from the heat exchanger to the wet exhaust.

 

[BruceK]

Since July is way too long.Take Comodave`s pvc version to a machine shop and get one made in metal?

 

[jgwinks]

Silicone is heat resistant, like 400+ degrees. They make baking pans out of it. It's also quite sticky so it should grip both the hose and barb better than some other materials. Salt water shouldn't bother it either.

 

[Lepke]

A short piece of thin wall hose on the bib and then the 7/8 hose over will give a tight seal. Any adapter made of metal will have to be protected from electrolysis. Or a wire connected to the HE that should be protected.