Quick Disconnect Coupler Wisdom Needed - Size / Type

[2fast916]

Hi!

I am in the process of trying to standardize the QD's on 3rd Function for two different tractors (an LS 40-hp & a Kubota B2650). I printed the following sizing chart on Letter size paper and compared to both tractors and attachments.

http://www.discounthydraulichose.com/v/vspfiles/downloadables/qd_sizechart.pdf

The LS shape and size lines up with ISO 7241-1 Series A 3/8" size, the Kubota lines up with ISO 7242-1 Series B 3/8" size, and some attachments that are used with the LS line up with AG QD's.

Since I'm new to hydraulic QD sizing and application, I was hoping someone could guide me by answering the following questions:

Q1: Is there any advantage to one particular type vs. another (i.e. Ag, 7241-1 A, 7241-1 B, flush or flat face)? Obviously the LS will have the higher flow requirements so, I would want to mirror that QD on the Kubota. I have also been previously guided from the forum that Ag will work with Series A but, not with Series B....so right now, I'm thinking I should switch the Kubota to Series A?

Q2: According to the sizing chart, it looks like I would need to buy 3/8" QD's for whatever type I've chosen to go with. Do I need to be worried about the size of the hydraulic hose thread diameter / pitch too? Or do I just order 3/8's QD's?

Any other guidance is more than greatly appreciated!!!

Thanks!

 

[2fast916]

In conjunction with this post, I emailed the same to Discount Hydraulics and there were the two responses received....thought I would post for others to be in the know:

 

[2fast916]

"The drawings are actual size. If you printed the chart at 100%, then the drawings should match your couplers correctly."

Ken Hutchinson
Customer Service
DiscountHydraulicHose.com

 

[2fast916]

"There are only marginal differences in performance between the three types of quick disconnects you mentioned. The AG style (ISO 5675) with a ball on the tip are by far the most common on farm equipment and tractors, but some people claim that the poppet style (the valve tip is pointed instead of round) provide improved flow characteristics.

As far as thread size, you do need to make sure your hoses have the right fittings or adapters on the ends to connect to your QDs. The most common thread is NPTF (pipe thread) in the same size as the QD. Following this tradition, our 3/8" ISO 7241 style QDs all have 3/8" NPTF threads. The ISO 5675 (AG Interchange) QDs come standard with 3/8" NPTF, but there are alternatives on our site with other threads also."

Ken Hutchinson
Customer Service
DiscountHydraulicHose.com

 

[Tractor Seabee]

Appears the 3/8 pipe tread is the common denominator. Pick the one you have the most of and change the others to match. My kubota has Parker fittings which are very common anywhere you go; your local hydraulic dealer probably has them in stock and don't cost an arm and a leg. You can buy them on line many places. Your tractor dealer's parts counter is probably the most expensive.

Ron

 

[2fast916]

Appears the 3/8 pipe tread is the common denominator. Pick the one you have the most of and change the others to match. My kubota has Parker fittings which are very common anywhere you go; your local hydraulic dealer probably has them in stock and don't cost an arm and a leg. You can buy them on line many places. Your tractor dealer's parts counter is probably the most expensive.

Ron

Thanks!

When you say Parker fittings...are these the Ag fittings? If so, that's what I'm leaning towards standardizing with since it seems to be very common in the U.S.

 

[rswyan]

I believe skid-steer flush-face couplers (ISO 16028) offer better flow characteristics and are certainly less messy as far as fluid loss goes (almost no fluid loss whatsoever as compared to ag style couplers) ... and female ISO 16028 QD's don't seem to be as inclined to collect dirt and debris as the ag style female QD's.

Don't understand why more folks don't go that route.

 

[kennyd]

Don't understand why more folks don't go that route.

$$$$ is the reason. FF couplers are a lot more money, that's whe we don't carry them.

 

[rswyan]

$$$$ is the reason. FF couplers are a lot more money, that's whe we don't carry them.

Depends on where one sources them I guess.

I replaced all of the ag style couplers I had on my equipment with SS/FF QD's from these guys for pretty cheap (no affiliation or remuneration, just a satisfied customer):

Flush Face Coupler

They're a China product ... but I find that in terms of hydraulic fittings, that's what I'm getting from other places as well ... including my local hydraulic shop.

 

[Tractor Seabee]

Your Discount Hose sheet; the Parker 60 under ISO 7241-1 Series B.
Be careful though on the ISO #. They all claim to be interchangeable but minuscule differences can cause them to leak. I would stay with only one brand name and not try to mix brands in the same ISO standard. With my Parkers I do not lose any fluid on connect/disconnect. 1500 hours on my BX with many many disconnects and no problems.

ron