SKU SKS-77 Categories , , Tags , Brand:
adjustable flat ell
SKU SKS-77 Categories , , Tags , Brand:

SKS Adjustable Flat Ell 45 to 90 Corner

Guides linesets around 45° to 90° turns on exterior walls. Durable PVC construction offers flexible routing and reliable protection.

Corners on exterior walls rarely land at a perfect angle, and that is exactly where the SKS Adjustable Flat Ell 45 to 90 Corner comes in. Inaba Denko’s Slimduct Flat 90 gives HVAC installers more flexibility when routing linesets around exterior wall corners.

Its adjustable design accommodates angles from 45° to 90°, making it useful when a fixed elbow does not match the installation path. As part of the Slimduct SD lineset cover system, the SKS creates a clean transition around corners while keeping exposed linesets covered and organized.

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Every installation has different wall angles and routing requirements. The Slimduct Flat 90 gives you flexibility at the corner while maintaining the clean profile and lineset protection of the Slimduct SD system.

Adjusts from 45° to 90°
Walls do not always meet at square corners. This elbow adjusts from 45° up to 90°, so one fitting handles multiple configurations on your job.

Sleek Two-Piece Design
The two-piece design gives the elbow a slim, low profile, so your lineset cover looks tidy and unobtrusive against the wall from nearly every angle.

Slip Prevention Pin
A built-in pin keeps the duct cover from slipping or sliding down, so your corner stays right where you put it long after installation day.

Durable PVC Protection
Made from durable PVC, it shields linesets from weather, UV exposure, and impact, giving outdoor HVAC installations dependable protection and a finish that holds up.

Multiple Colors and Sizes
Pick ivory, white, brown, or black for the SKS-77, or ivory and white for the SKS-100, so your cover blends into your wall beautifully.

Code No.Item No.ABPcs/Pkg
C-0538SKS-773-1/4″2-3/4″10
C-0539SKS-1004-1/4″3″10
* Color: SKS-77: Ivory, brown, black and white. SKS-100: Ivory and white
Slimduct SD BrochureSlimduct Instruction ManualSlimduct SD SpecsSlimduct SD Cross ReferenceSlimduct SD Test Report

Q: If sealing around joints is required, what kind of sealant should I use?
A: We recommend a UV-resistant silicone. Use it around the joints of your Slimduct Flat 90 and the rest of your Slimduct SD run so your seams stay sealed against sun and weather. For extra weatherproofing, you can browse our Tape & Putty range.

Q: To use as a reference when cutting the straight duct, what are the measurements of the product?
A: You can use the center of the straight duct hole for the screw fitting (half-open hole) as your guide. It sits at a 100mm pitch, or approximately 4″, and both ends are about 55mm, or approximately 2″. Mark your cuts on the SD Straight Duct with this in mind, and it will meet your Slimduct Flat 90 neatly.

Q: What are the product measurements?
A: Slimduct SD comes in three sizes, including 3″, 4″, and 5-1/2″. For the exact dimensions of the Slimduct Flat 90, check the technical specifications above, where you will find both the SKS-77 and SKS-100 sizes.

Q: Can I Also Use Slimduct SD indoors?
A: Yes, you can. Slimduct SD will not spoil the look of your room. If you are covering linesets inside, check out our Indoor Residential Cover options as well.

Q: What can I do to mount it on the wall?
A: You will want to use the specified parts from the Residential Elevating System.

Q: Can I use Slimduct SD with Slimduct PD (separate series)?
A: Yes, you can. Just use the PD-SD Coupler (PSDR) from the Slimduct PD series to connect the two, and you can mix both in one installation.

Q: Can I use SLIMDUCT SD for other things besides a lineset?
A: Yes, you can. Slimduct SD can cover other kinds of items too, as long as you install it following the installation manual.

Q: Do I need any specific tools to install the product?
A: No, you do not need specialized tools. All you need is a hand screwdriver, and it gives you better torque control than an impact driver does.

Q: What is the best way to make a straight cut?
A: While many tools are available, we recommend the Slimduct Cutter (VD-2100), specially designed to cut Slimduct SD. It gives you clean, straight edges on your duct before you connect your Slimduct Flat 90.

Q: Can I install the product in combination with another company’s lineset cover?
A: Please use only other Inaba Denko products for installation. Our warranty does not cover outside products, so it is best to stick with our system.

Q: I installed the lineset cover outside, and it deformed. What should I do?
A: If your cover is exposed to excessive heat beyond the tested ranges, it may deform. If you install it horizontally, make sure the inner piping is supported properly, or the weight could cause deformation. You can find the full details in the instruction manual.

Q: What are the protrusions inside the SW and the SK?
A: Those protrusions (pins) are meant to be inserted into a hole in the duct covers, so the cover does not slip downward in a vertical application. If you do not need them, you can simply remove them.

Caution

  • Slimduct SD is not waterproof. Seal longitudinal and lateral seams, screw heads, and wall penetrations with suitable weatherproof sealant or putty where waterproofing is required.
  • Slimduct SD duct and fittings are suitable for use and storage from -4°F to 140°F. Temperatures above 140°F may cause deformation. Protect installed components from direct and radiant heat.
  • Avoid using impact screwdrivers to attach Slimduct components or tighten fittings. Excessive torque can crack PVC components. Use hand screwdrivers for better torque control.
  • Use the SL-300 Strap Kit to retain the lineset inside the duct.

Why Choose Inaba Denko

We develop HVAC accessories with the installer and finished project in mind. Our products give contractors compatible components for routing and covering HVAC lines across a variety of residential applications.

Decades of Product Experience

We have developed HVAC accessories since 1978, bringing decades of product experience to lineset management solutions used by HVAC professionals across international markets.

Sizes for Real-Life Projects

Slimduct fittings come in 77 and 100 sizes to pair with matching straight duct, so your corners, runs, and covers all fit together without compromises.

Made for Professional Installations

Our products combine practical installation features with clean profiles, offering accessories designed around real installation conditions and professional-looking finished projects.

North American Product Support

Inaba Denko America supports distributors and HVAC professionals throughout North America with technical information, product documentation, and guidance for selecting accessories.

Best Used For

The SKS Adjustable Flat Ell is a natural fit for exterior wall turns where your lineset needs to change direction anywhere between 45° and 90°. It works with Slimduct SD lineset covers, keeping corners neat and professionally finished.

You will love Slimduct Flat 90 on outdoor ductless and unitary HVAC jobs where weather, UV rays, and impact are part of daily life and on installations where a clean, low-profile finish matters to your customer.

Build a Cleaner Lineset Installation with Inaba Denko

At Inaba Denko America, we bring Japanese-engineered HVAC accessories to distributors and contractors across North America, and we take pride in making your job simpler. Whether you are planning a single corner or a full lineset cover run, our team is happy to talk you through sizes, colors, and fittings. Reach out today and let us help you find the right fit.

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