Thank you, Scuzy, Tkeracer619, and Slief. Your insights are helpful. I considered the troubleshooting ideas you provided.
RPMs OF THE PUMP HEAD
- As for the number of RPMs the head is using, I am not sure; I have the flow rate set at 90 mL per minute, but I don't know what that translates into, as far as RPMs.
OCCLUSION ADJUSTER
- As for the occlusion adjuster, I was not paying attention to that, before;
- According to the manual for the pump head that Slief provided, the occlusion adjustment should be set at 4 for nominal performance, 5 for increased pressure/vacuum with reduced tubing life; and 2 or 3 for "longer life with less pressure and vacuum";
- I couldn't tell what the occlusion adjuster was dialed to because the marker line was not visible until I started turning the knob in different directions for a while;
- Ultimately, I got the marker line to display, and I suspect the occlusion was set too tightly, at 5 before; and
- I am resetting this occlusion knob way down, to 2 or 3, to see how it performs and how long it lasts--hopefully, it will still pump fluid correctly at the looser occlusion setting of 2 or 3.
SWITCHING TO PHARMED TUBING
- I'd like to try Pharmed tubing, if I can find the right size;
- Slief suggests that I figure out the dimensions of the 96410-24 tubing and switch over to US Plastics Corp Pharmed tubing for longer life, and I agree;
- According to the Cole-Parmer website, at https://www.coleparmer.com/i/masterflex-platinum-cured-silicone-tubing-l-s-24-25-ft/9641024?searchterm=96410-24, the dimensions of the Masterflex 96410-24 tubing are as follows:
- The tubing size is 24;
- Hose Barb Size (in) 1/4;
- Tubing ID (mm) 6.4 / 0.25 (in); but
- According to the Cole-Parmer website, "The outer diameter and wall thickness of Masterflex tubing is proprietary and we are therefore unable to share this information";
- Yet, I physically measured the Masterflex 96410-24 tubing, myself, and came up with:
- OD: ~ 12 mm; and
- Wall Thickness: ~ 2.4 mm.
- Thus, I am looking for Pharmed tubing with the following approximate dimensions:
- ID: 1/4";
- OD: ~1/2"; and
- Wall: ~1/16"
- Cross-referencing the specs of the Masterflex 96410-24 tubing with Pharmed products, it seems that the Masterflex tubing dimensions fall roughly in between the sizes of the PharMed-Tubing Model 57320 and 57321;
- Pharmed 57320 tubing is:
- ID: 1/4"
- OD: 3/8"
- Wall: 1/16"
- Pharmed 57321 tubing is:
- ID: 1/4";
- OD: 1/2"; and
- Wall: 1/8".
BOTTOM LINE
I could order
both products, Pharmed 57320 and 57321, to experiment and see which is better. Your thoughts?