Overview
Gates 3L220 V-belt in EPDM. Sapphire Scientific part number 37-072, listed in the parts schedule as Belt, 3L220 Gates EPDM.
This is a fractional-horsepower belt in the 3L section — a small belt, and a cheap one, on a machine where a failed belt stops the job.
Reading the belt code
The code is the specification, and it is worth being able to read it:
- 3L — the fractional-horsepower belt section: 3/8 inch top width, 7/32 inch thick
- 220 — the outside length in tenths of an inch, so 22.0 inches
Sapphire list several belts in the same 3L family — 3L190 (37-062), 3L240 (37-067) and 3L250 (37-090) among them. A belt of the right section and the wrong length will sit on the pulleys and will not tension correctly. Read the code off the old belt rather than measuring by eye.
Because 3L220 is an industry-standard size rather than a Sapphire-only part number, the belt can be sourced on that designation from any reputable supplier. Match the 3L section, not just the 22 inch length — a belt of the same length in a different section will not seat correctly in the pulley groove.
Confirmed application
Sapphire's own parts documentation for the Big Gulp 3500 flood extraction unit lists 37-072 as item 8 of the engine assembly (69-391), quantity one, alongside two 5V412 belts and the engine front pulley.
Note on revisions. The Big Gulp 3500 manual exists in more than one revision, and the engine differs between them — earlier books are Dri-Eaz branded with a Briggs & Stratton engine, later ones Sapphire Scientific with a Kohler. The 37-072 belt appears in the engine assembly either way, but if you are ordering against a specific machine, send us the serial number and we will check it against the correct revision.
We have not found 37-072 in the parts documentation for the Sapphire 370, 570 or 870 truckmounts. If someone has told you it fits one of those, ask us before ordering rather than assuming — we would rather check than have you fit the wrong belt.
Specifications
| Belt designation | 3L220 |
| Section | 3L (fractional horsepower) |
| Top width | 3/8 in (9.5 mm) |
| Thickness | 7/32 in (5.6 mm) |
| Outside length | 22.0 in (559 mm) |
| Material | EPDM |
| Manufacturer | Gates |
| Sapphire part number | 37-072 |
Why EPDM
EPDM belts run cooler and hold up better to heat and ageing than the older neoprene constructions. On a machine where the belt sits close to an engine and runs all day, that is the difference between a belt you replace on schedule and one that lets go on a job.
When to replace it
- Cracking on the underside — flex the belt and look into the base of the cracks. Fine surface crazing is age; deep cracks mean replace it now.
- Glazing — a shiny, hardened side face means the belt has been slipping.
- Missing chunks or a frayed edge — usually pulley misalignment, so check the alignment as well as fitting a new belt.
- Stretch — if it cannot be tensioned properly any more, it is finished.
A belt that keeps failing early is telling you something about alignment or tension rather than about the belt. Worth investigating before fitting the third one.
Frequently asked questions
What size is it?
3L section — 3/8 inch top width, 7/32 inch thick — and 22.0 inches outside length.
What machine does it fit?
It is listed in the engine assembly of the Sapphire Big Gulp 3500. See the note on revisions above, and send us your serial number if you want it confirmed against your machine.
Can I buy a 3L220 from anywhere?
3L220 is a standard industrial size, so yes. Match the 3L section as well as the length, and buy a reputable belt — a cheap belt on an engine drive is a false economy.
Is this the same as the 5V belts on the same machine?
No. The Big Gulp 3500 engine assembly also takes two 5V412 belts, which are a different section entirely. Order by the code on the belt you are replacing.
Do I need to replace them as a set?
Where a drive uses matched belts in a multiple-belt set, yes — replacing one alongside worn ones loads the new belt unevenly. This is a single belt in its position, so it can be replaced on its own.
How long should it last?
There is no published figure and it depends on hours, tension and alignment. Sapphire's own warranty treats factory-fitted belts as a maintenance item covered for 500 hours, which gives you a sense of the order of magnitude rather than a replacement interval. Inspect it and replace on condition.
Send us the code off the old belt, or the machine and its serial number, and we will confirm the right belt before you order.
More Belts, other Sapphire drive belts including the 5VX510 blower belt, and the full range in Parts & Maintenance.
