A few years ago, I hand-knit a sleeve/cozy for the hose on my CPAP machine. It used one whole skein of Big Twist Sincerely Ombres in Gray Denim. I knit it flat on size 7 needles, then (without breaking the yarn) left a long tail and used a 5mm crochet hook to single-crochet the long seam together on the inside, which would make it easier for me to undo the work and reuse the yarn later if I decided to redo the hose sleeve, since that was my first attempt at knitting one.
It was around that same time when I first started hearing about the wonderful circular knitting machines like the Addi, Sentro, etc., and after spending some time studying what the machines could do, I was certain I could reknit this hose sleeve using a 22-needle machine. It would be a couple of years before I'd decide to invest in the Addi Express Professional, but that time finally came, and this is the first item I knitted on it.
I cast on with waste yarn for about 12-13 rows then started knitting with some Grey Heather Red Heart Super Saver. When I hand-knit the hose sleeve, it was only 17 stitches wide, and since the Addi has 22 needles, I wanted to be sure the reknit sleeve would be long enough, so I knit with the gray Red Heart yarn for 48 rows (about 11 inches). Then I changed to the Big Twist yarn and continued knitting. The counter read 358 rows when I stopped knitting with the Big Twist yarn and switched back to waste yarn for another 12-13 rows before casting off.
I had left a long tail (about 6 yards) before starting the Red Heart yarn in the machine. I used that long tail to pick up and SC in each stitch from the waste yarn on the cast-on end. Then I continued to SC in each stitch around in a continuous spiral (without joining at the end of rounds) until the yarn ran out. There was enough yarn for about 4 rounds of SC on that end. I finished off with the gray yarn and then removed the waste yarn from that end of the hose cover.
At the other end of the hose cover I had also left a long tail of the Big Twist yarn. I used that tail to pick up and SC in each stitch from the waste yarn. Then I chained 16 to form a long loop for the frame of my mask to slip through (to help hold the hose sleeve in place during use), then SC in the next stitch to join the loop to the edge of the hose sleeve, and SC in the next 10 stitches and chained 16 again for the second mask loop. I joined that loop with a SC in the next stitch and SC in all the stitches until I was back to where the first loop chain began. I put a SC in each chain of the loop, then continued with SC around the edge of the hose sleeve until reaching the second loop chain. I repeated putting a SC in each chain and then continued in SC along the edge of the hose sleeve until the yarn was about to run out and finished off there.
I think the extra stitches in the width of the Addi-knit hose sleeve will make it a little bit easier to put on and take off this version of the hose sleeve compared to my hand-knit version. These yarns are nice and soft (after machine washing and drying), so they make a nice hose cover.