PARTS · DIAPHRAGMS · LMI
LMI Liquifram Diaphragms — Size Codes, SP Kits & Replacement Guide
Compatible and OEM-grade Liquifram® diaphragms for LMI Series A, AA, B, C and P metering pumps. Find your size code, match the SP spare parts kit, and order at factory-direct prices.
1. Find Your Diaphragm Size Code
The Liquifram® size code is stamped on the back of the original diaphragm and on the spacer/disk behind it. If the old part is already off the pump, match the first three characters of your pump model number against this chart (from LMI's published compatibility data):
| LMI Pump Series (first 3 chars) | Diaphragm Size Code |
|---|---|
| A×1 | SC 1 |
| A×4 | SC 1 |
| A×5 | SC 2 |
| A×6 | SC 3 |
| AA×4 | SC 0.5 |
| AA×5 | SC 0.9 |
| AA×6 | SC 1.8 |
| AA×7 | SC 0.5 |
| AA×8 | SC 0.9 |
| AD×1 | SC 1 |
| AD×4 | SC 2 |
| AD×5 | SC 3 |
| AD×6 | SC 4 |
| B×1 | SC 0.9 |
| B×2 | SC 0.9 |
| B×3 | SC 1.8 |
| B×4 | SC 3.0 |
| C×0 | SC 0.9 |
| C×1 | SC 1.8 |
| C×2 | SC 1.8 |
| C×3 | SC 3.0 |
| C×4 | SC 6.0 |
| P×2 | SC 0.5 |
| P×3 | SC 0.9 |
| P×4 | SC 0.5 |
| P×5 | SC 0.9 |
| P×6 | SC 1.8 |
2. DOSEPARTS Quote SKUs by Size Code
Order by size code — the same diaphragm fits every LMI pump series that uses that code. Tell us your pump model for confirmation:
| SKU | Size Code | OEM Part No. (ref) | Typical Series |
|---|---|---|---|
| DSP-LMI-DIA-05 | SC 0.5 | 30916 / 37341 | AA×4, AA×7, P×2, P×4 series |
| DSP-LMI-DIA-09 | SC 0.9 | 26041 / 30917 / 10102 | A×1, A×4, AA×5, AA×8, B×1, B×2, C×0, P×3, P×5 series |
| DSP-LMI-DIA-18 | SC 1.8 | 10105 / 31420 | A×5, AA×6, B×3, C×1, C×2, P×6 series |
| DSP-LMI-DIA-30 | SC 3.0 | 31419 / 37341 / 37861 | A×6, B×4, C×3 series |
| DSP-LMI-DIA-60 | SC 6.0 | 37863 / 25719 | C×4 series |
OEM part numbers are reference numbers from LMI's published spare parts documentation — our parts are compatible replacements, not OEM-branded.
3. SP Spare Parts Kit Reference (Standard Liquid Ends)
LMI's SP kits bundle everything needed for one liquid-end rebuild: Liquifram®, spring, seal rings, check balls and shaft seal. Reference table below is from the LMI SP kit instructions (Group 1, standard liquid ends):
| SP Kit | Size | Liquifram® | Spring | Seal Ring | Ball | Shaft Seal |
|---|---|---|---|---|---|---|
| SP-151FS | 0.5 | 37341 | 10339 | 10107 | 10444 | 10973 |
| SP-U8 | 0.5 | 37341 | 10339 | 29443 | 10338 | 10973 |
| SP-U9 | 0.5 | 37341 | 10339 | 10407 | 10338 | 10973 |
| SP-09 | 0.9 | 26041 | 37341 | 29443 | 10338 | 10973 |
| SP-89 | 0.9 | 10102 | — | 10107 | 10338 | 10973 |
| SP-91H | 0.9 | 30917 | 37341 | 10107 | 10338 | 10973 |
| SP-92L | 0.9 | 30917 | 37341 | 29443 | 10338 | 10973 |
| SP-92V | 0.9 | 30917 | 37341 | 10207 | 10338 | 10973 |
| SP-U1 | 0.9 | 30917 | 37341 | 10407 | 10338 | 10973 |
| SP-U3 | 0.9 | 10102 | 37341 | 10107 | 10444 | 10973 |
| SP-U7 | 0.9 | 30917 | 37341 | 29443 | 10338 | 10973 |
| SP-79 | 1.8 | 10105 | — | 10107 | 10338 | 10973 |
| SP-U2 | 1.8 | 31420 | 37341 | 10407 | 10338 | 10973 |
| SP-U4 | 1.8 | 10105 | 37341 | 10107 | 10444 | 10973 |
| SP-U10 | 1.8 | 31420 | 37341 | 29443 | 10338 | 10973 |
| SP-15 | 3.0 | 31419 | 37341 | 10407 | 10338 | 10973 |
| SP-20 | 3.0 | 31419 | 37341 | 10128 | 10138 | 10973 |
| SP-26 | 3.0 | 31419 | 37341 | 10228 | 10138 | 10973 |
| SP-29 | 3.0 | 31419 | — | 10128 | 10138 | 10973 |
| SP-U5 | 3.0 | 31419 | 37341 | 25128 | 10138 | 10973 |
| SP-U17 | 3.0 | 31419 | 37341 | 29443 | 10338 | 10973 |
| SP-U18 | 3.0 | 37341 | 37341 | 25128 | 10338 | 10973 |
| SP-U19 | 6.0 | 37863 | 37341 | 25128 | 10338 | 10973 |
4. High-Viscosity & Stainless-Steel Liquid Ends
Group 2 kits (high-viscosity liquid ends) and Group 3 kits (stainless-steel liquid ends) use different spring, seal-ring and ball part numbers:
| HV Kit | Size | Liquifram® | Spring |
|---|---|---|---|
| SP-155FS | 0.5 | 30916 | 25558 |
| SP-156 | 0.5 | 30916 | 25558 |
| SP-85HV | 0.9 | 30917 | 25558 |
| SP-86 | 0.9 | 30917 | 25558 |
| SP-75HV | 1.8 | 31420 | 25558 |
| SP-76 | 1.8 | 31420 | 25558 |
| SP-25HV | 3.0 | 31419 | 25558 |
| SP-20HV | 3.0 | 31419 | 25558 |
| SP-620HV | 3.0 | 37861 | 25558 |
| SP-625HV | 3.0 | 37861 | 25558 |
| SP-30HV | 6.0 | 25719 | 25558 |
| SP-35HV | 6.0 | 25719 | 25558 |
| SP-630HV | 6.0 | 37861 | 25558 |
| SP-635HV | 6.0 | 37861 | 25558 |
| SS Kit | Size | Liquifram® | Seal Ring |
|---|---|---|---|
| SP-157 | 0.5 | 30916 | 10407 |
| SP-97 | 0.9 | 30917 | 10407 |
| SP-77 | 1.8 | 31420 | 10407 |
| SP-27 | 3.0 | 31419 | 25128 |
| SP-627 | 3.0 | 37861 | 25128 |
| SP-37 | 6.0 | 25719 | 25128 |
| SP-637 | 6.0 | 37863 | 25128 |
5. SP-U Kit → LE Liquid End Compatibility
Find the "LE-" designation printed on your pump's liquid end housing or original manual, then match the kit:
| SP Kit | Fits LMI Liquid Ends |
|---|---|
| SP-U1 | LE-81S, LE-81T, LE-82T, LE-85S, LE-85T, LE-91S, LE-91T, LE-92S, LE-92T, LE-94, LE-94S, LE-95S, LE-95T, LE-196, LE-196S |
| SP-U3 | LE-81FS, LE-91FS |
| SP-U7 | LE-190, LE-190S, LE-191, LE-191S, LE-192, LE-192S, LE-193, LE-193S, LE-198, LE-198S |
| SP-U8 | LE-150, LE-150S, LE-151, LE-151P, LE-151S, LE-152, LE-152S, LE-158 |
| SP-U17 | LE-12, LE-12S, LE-112, LE-112S, LE-118, LE-118S |
| SP-85HV | LE-85HV, LE-86PBA |
| SP-151FS | LE-151FS |
6. Replacement Tips
- ✓ Replace as a set: LMI recommends replacing the Liquifram®, check balls, seal rings and injection check valve spring together — the SP kit bundles exactly this set.
- ✓ Stroke setting: after installing a new Liquifram®, run the pump and set stroke to 90% (A/B/P series and C10-C12/C70-C72/C76/C90-C92), 70% (C13/C14/C73/C74/C77/C93/C94), or 100% for M series, so the diaphragm centers flush with the spacer.
- ✓ Shaft seal: only replace when the Liquifram® has ruptured or the seal shows damage.
- ✓ Replacement interval: LMI recommends annual replacement of elastomeric components; pumps dosing sodium hypochlorite or aggressive acids may need service more often.
Frequently Asked Questions
How do I find my LMI diaphragm size code?
The size code is stamped on the back of the original Liquifram® diaphragm and on the spacer or disk behind it. If the pump is still assembled, use the model chart above — the first three characters of the model number (e.g. A75 for an LMI A751-117) map directly to a size code.
Are your LMI diaphragms genuine OEM parts?
We supply both: high-grade compatible diaphragms (dimensionally identical, PTFE-faced, tested to OEM pressure ratings) and genuine OEM where requested. Most plants run compatible parts at a fraction of OEM cost.
Which material is the Liquifram® diaphragm?
LMI's Liquifram® is a PTFE (Teflon®-faced) diaphragm with a bonded elastomer body. Our compatible diaphragms use the same PTFE-faced construction for chemical resistance and flex life.
What is the difference between an SP kit and an RPM kit?
SP kits are liquid-end spare parts kits (diaphragm + check valves + seals). RPM Pro-Pac® kits add drive-side components (oil seal bellows, cartridge valve assemblies) for a full preventive maintenance rebuild. Send us your pump model and we will recommend the right one.
Can I order a single diaphragm instead of a full kit?
Yes — order by size code (SKU DSP-LMI-DIA-05 through -60) or tell us your pump model. Sample orders of one piece are welcome.
Data sources: LMI Milton Roy SP Spare Parts Kits Instructions (public PDF), LMI instruction manuals, and Cleanflow LMI product documentation (2026-08-25). OEM part numbers are reference only; DOSEPARTS supplies compatible replacements unless OEM is explicitly requested.
Need the Right Pump Part Fast?
Factory-direct pricing on compatible diaphragms, valve cartridges, PMK kits and liquid ends for LMI, ProMinent, SEKO, Milton Roy and Pulsafeeder pumps. Send your pump model and get a quote within 24 hours.