NEW PRODUCT ANNOUNCEMENT: a new Innerduct Pulling Eye for 1-3/4″ (or 50mm) nominal duct! This “carrot” fills out the 00604 Series Lugged pullers to cover any duct between 3/4″ and 2″ – including a 1-1/4″ fine-thread version especially for thin-walled telecom duct. That should satisfy any wascally wabbit!
Between the Lug, Clevis and Swivel styles, we’ve got every connection method covered. The sharp teeth and cutting surfaces are tapered to bite into polyethylene duct and not let go until your pull is complete.
Because the Lugged 00604 and Clevis 00605 carrots have no moving parts and completely seal the duct, they’re ideally suited to HDD applications. The Swivelling 00615 Series combines the tapered bite with a rotating clevis head to minimize your leading-end connections when pulling new ductwork through existing outer ducts.
Just in time for Easter, these carrots are on special for the month of April! Contact your local DCD distributor for details, and ask about our Easter Egg bonus for quantity-break purchases!
DCD Design provides two Safe Working Load limits for our 00505 Series Line Swivels, depending on whether you’re pulling Underground or Overhead. What’s the difference? RISK.
A Safe or Maximum Working Load without a Safety Factor is incomplete – you don’t know where you stand. One company’s Overhead Swivels may only have a 3:1 Safety Factor, when every other component has been rated 5:1. Where’s the weak link?
When you’re stringing overhead lines, a 5:1 Safe Working Load is typically chosen to suit the safety factors applied to pulling rope and grips. I say “typically” because safety factors and the resulting safe working loads are user-dependent.
Occupational safety requirements are a minimum level of protection. Risk management demands a greater level of protection if a failure will have catastrophic consequences.
You don’t want to see a failure in an overhead job because when things fall down, they land on other things! You can reduce the risk of failure by choosing a larger safety factor, but you’re limiting your maximum load. There has to be a compromise!
Underground, a 3:1 Safe Working Load can typically be applied. A failure is still possible, but the risk of damage or injury is reduced. You can “afford” to increase your maximum load. So the same Line Swivel can have two Safe Working Loads, depending on the application.
If you’re comparing line stringing swivels for overhead use, know the Safety Factors built into your equipment and make sure you’re getting the whole story. DCD Line Swivels have a happy ending.
We have a new video on Youtube, showing how to change out shoulder bolts on the big 00620 Series Duct Pullers! The 10″ & 12″ Pullers have removable shells so that you can swap in the appropriate size, depending on your duct’s wall thickness. We have complete Pullers available with SDR9, 11 or 17 shells, and shell kits are available for field change-outs.
In other news, DCD Duct Pullers have been put to work in the material science lab, gripping tensile samples of C900 PVC pipe. S&B Technical Products presented a paper at the UCT Expo in Tampa recently, detailing their testing of the Bulldog Restraint System for AWWA C900 PVC pressure pipe. The assembled joints are as strong as the pipe, and can be installed by trenchless methods like Horizontal Directional Drilling.
Our 00620 & 00621 Series Duct Pullers were matched to the appropriate inside wall diameters for the PVC pipe – because PVC is a stronger material, the ID is greater than expected for a nominal pipe diameter. (We had to use a couple of metric-sized pullers to match it all up!)
Now we’re working with S&B Technical to optimize the Pullers’ expanding shells for PVC pipe.
In other Duct Puller news, DCD Design is encouraging a visual inspection of all 12″ Duct Pullers in service to check the length of the shoulder bolts securing the expanding shells into the faceplates.
Bolts that are too short and don’t seat properly in the faceplate – see the photo – can be exchanged by contacting DCD Design.
There’s a Maxi-DUB swivel leaving our Service Center this week, serial number 250-102. The first three digits are the tonnage – 250 tons. The second three digits are the production number – the second one made. (That pattern is standard for any of our big-rig swivels, btw.)
This swivel is something special: it was built in the fall of 1998, and delivered for service on the 12th of November that year. It’s probably the oldest Maxi-DUB swivel in service these days! *
We’ve seen it in for service three or four times over the 11 years since. When it came in this year for a routine service, I asked the mechanic to get a few photos, thinking I could write it up to show how regular maintenance will prolong the lifespan of the swivel.
I hadn’t expected it to be so banged up after a year in service! Still, the mechanic worked through it, cleaned it up, and replaced the necessary parts. It looked worse than it was.
Others have tried to duplicate the Maxi-DUB swivel but after years of service and hundreds of swivels, our patented design continues to prove itself. Other manufacturers can’t claim that.
* By the way, if you’ve got a record-breaker, let us know! Send us a photo and we’ll feature it here.
Inquiries for wire mesh pulling grips come in from all over the place, and it’s interesting to see how local tradition will affect terminology.
The length of a grip depends on where you’re standing. If you’re reading a North American catalog, the length of the mesh is taken at the grip’s nominal diameter. That is: it’s measured when it’s fitted around the cable it’s pulling. This is the engaged length of the grip; the eye and the overall length are measured separately.
Other locales will measure the “free length” of the grip, when it’s hanging on the wall. The free length can be half-again as long as the fitted length, so it’s not a clear indicator by itself of the size of the grip in service. The comparison below shows the difference: a free length of 35″ can contract the mesh to just 21″ when it’s installed.
The wire weave of a pulling grip is flexible, and the grip will contract as the tube diameter increases. Variation of a couple inches in the free length is typical, and the fitted length will vary depending on the actual diameter of the cable.
We’ve added a new feature to the website and incorporated a poll question on the main page. Take a moment to plug your preferred projectile for line blowing: foam, parachute, cone or grocery?
Results will be tallied by month-end.
Pardon the pun, but how often do you get to say that in public?!
We’ve got a range of line-blowing products on special this month – mix and match to build a tool kit that works for you! All projectiles are available individually or as kits, in a variety of sizes and weights: from durable Line Darts to our unique Ultralight Birds and Parachutes.
Start with a high-pressure Control Valve that fits to your compressor, or choose the DCD Power Blower for a powerful self-contained unit. Both options have their advantages.
The Control Valve uses twist-lock fittings to mount to a standard air hose, and mounts to threaded Innerduct Seals for a secure, air-tight seal. Larger ducts can use the advanced Duct Seal Body with quick-change polyurethane Seal Kits.
The inner bore of the Control Valve is smoothed to ensure that nothing can get hung up midway through the job. Our Valve also comes complete with three different rope guides – others don’t!
The Power Blower is a portable unit with parallel, twin motors to provide the maximum pressure available in this class of line blowers: up to 30% higher than the competition. The motors are individually fused and switched, so use one motor when that’s all you need or both when you’ve got a 30 amp breaker at your disposal!
Check out the whole range of Line Blowing Equipment here and follow through with pulling twine and Bull-Line pull tape!
Channel
Products