I had a customer ask how long a swivel will last in an unusual application, and I had to sit down and think about how to provide an answer that made sense. In short, the answer is “It depends!”
It depends entirely on how the swivel is maintained and the conditions it’s working in. The bearing manufacturers have a standard calculation that I use to assess a bearing lifespan, comparing the actual applied load to the bearing’s rated load. (Bearings are defined by their Basic Life Rating: the maximum load they can carry at a constant speed so that 90% of a representative sample will reach one million revolutions.)
At the Safe Working Load and standard conditions, a swivel’s bearing will last for 1 million revolutions, for example. At one-half the SWL, it will last significantly longer, 8 million revolutions. Both these calculations presume the swivel and grease are not compromised.
In short, the harder you work a swivel, the shorter the lifespan – and the relationship is not linear! Look at the above comparison: one-half the load leads to eight times the revolutions.
The load on the swivel is one factor. The care and maintenance you provide for the equipment is another major factor.
To last for 8 million revolutions, the swivel and its bearing will need lubrication at regular intervals. Since the frequency of maintenance will directly affect the level of reliability, we recommend lubrication after every pullback to keep the grease in the best possible condition. (And a thorough cleaning besides!)
In other news: we’ve had requests for a lengthened version of the Plow Grip Flip video, to fully illustrate the parts order when rebuilding after maintenance. I’ll take a crack at that when we get back from next week’s ICUEE show in Kentucky.
And if there’s anything else you’d like to see, let us know! We’ve got a few ideas for new videos, but I’m sure we could get yours on the list.
The DCD Plow-Grip is a quick and easy connection in three different sizes, specifically designed to install PVC or PE duct by Vibratory Plow. It’s perfect for agricultural applications because it installs and removes in seconds. It’s built from stainless steel with hardened chain links and hardened expanding jaws that grip the inside of the ducting.
Though you can’t tell by looking at it, the Plow-Grip sleeve is reversible to fit various outside and inside diameters for ducting. All you need is a 9/16″ wrench – see our new video. Look for the groove around the sleeve – that’s the smaller outside diameter! The sleeve will cover 80# and 100# PE duct and Sch.40 up to SODR 26 PVC duct.
To assemble the Plow-Grip to the ducting, compress the head into the sleeve to contract the hardened steel jaws. The Plow-Grip can then be sleeved over the ducting. When the head is released, the jaws expand inside the duct and bite into the duct wall. As the pulling load is applied, it increases the bite of the jaws. When the pull is complete, pushing the head down will again contract the jaws allowing the Plow-Grip to be removed from the ducting.
The International Construction & Utility Equipment Exposition – ICUEE – is fast approaching! We’re getting our ‘duckts’ in a row: our demo trailer is getting detailed and restocked, our show space is getting prepared and we’re finalizing our schedule.
We’ll have 4-5 product experts on hand for the 3 days: Neal, our Engineering Manager; John, our Overhead specialist; Ryan, the Sales Manager; Ted, our General Manager; and Jon, Special Projects Manager. Get your hands on our installation equipment, get a catalog, and get one of our special giveaways while you can!
Date: October 6th – 8th, 2009
Place: Louisville, Kentucky, USA / Kentucky Exposition Center
Website: www.icuee.com
What is ICUEE?
ICUEE, the International Construction & Utility Equipment Exposition, is the premier international demonstration exposition and education resource for the construction and utility industries, focusing on the following sectors:
* Electric
* Phone and Cable
* Sewer and Water
* Gas
* General Construction
* Landscaping
* Public Works
DCD Design has a range of Cable Installation products, for both underground ductwork and overhead lines. One recent example, quite literally in our backyard, involved a set of powerlines being installed to new towers over a railway, marina and access road by Pacific Electrical Installations.
The latest monthly promotion is up: DCD duct rodders! We’ve been producing duct rodders for years in a range of lengths and rod diameters, including detectable rod. Here’s the Top Five Features that set us apart:
1. Frames and rod cages are built to our specifications to be light weight and strong.
2. Our frames are compact and maneuverable to fit into smaller work areas.
3. Our fiberglass rod is pultruded* to provide excellent longitudinal strength with the flexibility for corners.
4. We have a wide array of stainless steel end accessories to suit any application.
5. Our rodders are made to order – call us before noon (Pacific time) and we can usually ship same day.
*And a quick definition: Pultrusion is a continuous process of manufacturing of composite materials with constant cross-section whereby reinforced fibers are pulled through a resin and into a heated die, where the resin undergoes polymerization. Because the fibers are held in tension, the resulting form exhibits superior properties compared to a similarly extruded form.
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