Best method to connect dosing tube to Mur-Loc fitting?

[dallast]

I purchased a Mur-Loc adapter from BRS, but my tubing is diameter is very small and took a tremendous effort to get on the barb fitting. I did get it on but I now the dosing pump (Coral Box) can’t seem to lift the fluid out of DIY Voss dosing container. Any suggestions? Do I have a leak in the system?

 

[Dennis Cartier]

You either have a leak, or your dosing pump head is not maintaining constant vacuum. The lower end dosing pumps commonly require a check valve on the input side to maintain the vacuum needed to lift the fluid.

For connecting dosing pump hoses to the typical 1/4" tubing, the John Guest adapters that BRS and others sell are great for larger sized dosing tubes. They work great for size #17 or #16 or #18, but are near impossible for smaller tubes found on the dosing heads targeted at lower flows.

For connecting those, you will need to get hose adapters from other vendors like US Plastics or Nordson Medical. Us Plastics tends to be pricey and shipping is high, at least for me, in Canada. For Nordson, you need to buy the connectors by the bag of 50 or 100, but in my case, they were far more affordable than buying a few from US Plastics.

To make connections to 1/4" tubing that is removable, I suggest using a .170" barb to a luer connection, and then a luer to an appropriate sized barb.

Here is an example of two luer type connectors for connecting 1/4" tubing to super tiny LS13 hosing on a Masterflex pump.

Dennis

 

[dallast]

You either have a leak, or your dosing pump head is not maintaining constant vacuum. The lower end dosing pumps commonly require a check valve on the input side to maintain the vacuum needed to lift the fluid.

For connecting dosing pump hoses to the typical 1/4" tubing, the John Guest adapters that BRS and others sell are great for larger sized dosing tubes. They work great for size #17 or #16 or #18, but are near impossible for smaller tubes found on the dosing heads targeted at lower flows.

For connecting those, you will need to get hose adapters from other vendors like US Plastics or Nordson Medical. Us Plastics tends to be pricey and shipping is high, at least for me, in Canada. For Nordson, you need to buy the connectors by the bag of 50 or 100, but in my case, they were far more affordable than buying a few from US Plastics.

To make connections to 1/4" tubing that is removable, I suggest using a .170" barb to a luer connection, and then a luer to an appropriate sized barb.

Here is an example of two luer type connectors for connecting 1/4" tubing to super tiny LS13 hosing on a Masterflex pump.

Dennis

Thank you Dennis for your fantastic reply! I was starting to think that I was having some sort of leak in my line as well, but it might be the pump head as you suggested as it is a few years old. Thank you for the parts suggestions as well! I really didn’t think they were even manufactured. I will do some more investigating before I look to order.