Stuffing Box Hose Clamps

This is an issue I encounter on an all too frequent basis; the hose clamps for stuffing boxes look pristine on the upper hemisphere, in fact they look good from the 7:00 o'clock position all the way around to the 5:00 o'clock position. It's at the 6:00 o'clock position where the problem begins. This is the area that's so often wet from leaking packing or seals, and it's where clamp bands suffer the most. In the attached photo (looking upward at the bottom of the stuffing box hose), taken aboard a vessel I inspected recently, the band has actually parted, I see this a lot. The top of the band remains in place by virtue of the fact that it's stuck to the hose after being there for years.

Bottom line, inspect your stuffing box hose clamps regularly, including and especially the bottom section, you may need a mirror or point and shoot camera to do this. As an aside, the 'folded spot weld' used on most T bolt style clamps is particularly susceptible to crevice corrosion. Be sure the spot weld area is located on the upper hemisphere of the hose. I recommend saturating the fold with CRC HD Corrosion Inhibitor, or use the style that relies on an interlock rather than spot weld.

This two part article goes into detail about clamp selection and installation, including the T-bolt issue...

https://stevedmarineconsulting.com/hose-clamps-part-i-design-and-selection/

https://stevedmarineconsulting.com/hose-clamps-part-ii-installation-and-use/

(In Kaohsiung, Taiwan)

What a timely post particularly for me. I am working on replacing one of my fuel tanks this winter. I will have to pull the engine and stack it above the other engine in order to get to the tank. While the engine is out I plan on replacing all the hoses and clean up the part of the engine room that I have difficulty getting to. One of the items on my list is the stuffing box hose. Do you have a particular brand of clamps that are recommended? Is there a really good brand of hose to use for the stuffing box?

The article details the attributes of a good clamp, non-perforated, all stainless, for stuffing box should be 316. AWAB and Norma make these, among others. If you use a T bolt style, try to get the interlocking variety, oil the stud threads as they are prone to galling, and coat the band with CRC HD for an added measure of corrosion protection.

Not just any hose can or should be used for stuffing boxes, it should be 5 ply, see https://stevedmarineconsulting.com/conventional-wisdom-for-conventional-stuffing-boxes/ for more details.

(In Kaohsiung, Taiwan)

Hi Steve - my engine is out with other work and am re-thinking the stuffing box setup I have on my 1970 Willard 36 (Perkins 4.236). Would appreciate your feedback:
1. For compression on traditional boxes, do you prefer single large gland nut that encircles the stuffing box; or a yoke with two ears where a stud passes? Many years ago, I replaced the original bronze large gland nut style with the 'yoke' style as the male threads where the large nut landed had eroded over the years (they were very fine threads) so compressing the packing was difficult. Wonder your thoughts on the different styles?
2. Dripless systems. Until recently, I was an "old school" traditional stuffing box adherent: if the stuffing box is easily accessible, go traditional as failures in a PSS-type system can be catastrophic. If the stuffing box is not easily accessible (I owned a 1972 Willard 30 Searcher where the SB was buried beneath a small cabinet), then a PSS is worth the risk. But after 20-years or so, the only failures I have heard of on a dripless system was from improper install - secondary lock-screws were not installed and seating ring back-away. What's your best thinking?

As always, thanks in advance. Very much appreciate your being so generous with your time and knowledge. Speaks volumes

Peter

Thanks Steve, great article. I appreciate the response.

mvweebles said:

Hi Steve - my engine is out with other work and am re-thinking the stuffing box setup I have on my 1970 Willard 36 (Perkins 4.236). Would appreciate your feedback:
1. For compression on traditional boxes, do you prefer single large gland nut that encircles the stuffing box; or a yoke with two ears where a stud passes? Many years ago, I replaced the original bronze large gland nut style with the 'yoke' style as the male threads where the large nut landed had eroded over the years (they were very fine threads) so compressing the packing was difficult. Wonder your thoughts on the different styles?
2. Dripless systems. Until recently, I was an "old school" traditional stuffing box adherent: if the stuffing box is easily accessible, go traditional as failures in a PSS-type system can be catastrophic. If the stuffing box is not easily accessible (I owned a 1972 Willard 30 Searcher where the SB was buried beneath a small cabinet), then a PSS is worth the risk. But after 20-years or so, the only failures I have heard of on a dripless system was from improper install - secondary lock-screws were not installed and seating ring back-away. What's your best thinking?

As always, thanks in advance. Very much appreciate your being so generous with your time and knowledge. Speaks volumes

Peter

Click to expand...

I suppose if I had to choose I'd go for the twin studs, they never get stuck, easier to adjust, just be sure to use two wrenches to lock the double nuts against each other.

As far as dripless go, I tell my clients, if you are comfortable with adjusting a conventional stuffing box, it is as reliable as you can get. If you want dripless, then which ever one you choose shouldn't shouldn't leak even if you stand on it. Here's the companion dripless article https://stevedmarineconsulting.com/keeping-your-bilge-dry-with-dripless-stuffing-boxes/

Otto von Bismark said, "Only a fool learns from his own mistakes, a wise man learns from the mistakes of others". Always happy to let others benefit from the many mistakes I've made;-)

Great post Steve. My boat came with all perforated Home Depot clamps. I bought 4 bags of AWAB clamps in different sizes and started replacing. One in four clamps that I removed was cracked through at the bottom and stuck on top, just as you described. My surveyor had noted it in his survey, so I had extra incentive to get it cleaned up quickly.