The 437c single spring mechanical seal is Seal House USA’s N Line replacement for the PS-437 — an N-11 crimped-head seal for a 3/4 in. shaft with a 1.275 x .281 cup seat, used in Bell & Gossett pumps and sold by them as Universal Kit #2. Equal to the PS-437, not an original PS part. Built to OEM-equivalent standards or higher.
Specifications
Shaft Size3/4 in.19.05 mm
Head TypeN-11crimped head · John Crane 21
Head ODCONFIRM in.
Working Length0.875 in.operating height
Seat OD1.275 in.
Seat Thickness0.281 in.
Seat MountCup mounted
Metal PartsStainless Steel
Single spring · elastomeric bellows · non-directional, runs either rotation · carbon or silicon carbide faces, Nitrile or Viton elastomers
Choose Your Seal Material3 seal materials available. Same seal, same dimensions — only the seal faces and rubber parts change. Find what your pump runs, then choose that option from the drop-down menu above.
| Standard – Carbon/Ceramic/NitrileCarbon face, ceramic seat, Nitrile rubberCAR/CER/NIT · BCDJF · Max 225°F |
Clean water at neutral pH — hydronic heating, chilled water, booster and general-service pumps. This is the standard build. |
| Upgrade – Carbon/Ceramic/VitonCarbon face, ceramic seat, Viton rubberCAR/CER/VIT · VCDJF · Max 400°F |
Your pump runs hot, or handles glycol, oils, fuels, bleach or other chemicals that break down standard Nitrile. |
| Top gradeHeavy Duty – Silicon Carbide/VitonSilicon carbide face and seat, Viton rubberSIC/SIC/VIT · VLDLF · Max 400°F |
Gritty or dirty water, condensate with scale, or any pump where seals keep wearing out early. The hardest faces we offer. |
Not sure which material? Call or text a photo of your pump nameplate to 561-414-1046 — no purchase required.
Cross ReferencesFind your pump brand, then match the number on your old seal or nameplate.
| Pump Brand |
OEM Part No. |
Nameplate & Notes |
| Bell & Gossett (A Xylem Brand) |
172553 · 185260 · 186433 · 186499 |
1512-PD39, BPD39 and 60A — sold by Bell & Gossett as Universal Kit #2 |
Seal House USA provides aftermarket replacement parts. The 437c is equal to — not manufactured by — the listed OEMs or US Seal Mfg. Any OEM and PS names or numbers are used strictly for cross-reference. We are an independent supplier.
Other part numbers & search terms
Part number: PS-437 = PS437 = PS 437 = 437 = 437c = 437 C = 437-c
Bell & Gossett: Kit #2 = Kit 2 = Universal Kit #2 · 172553 · 185260 · 186433 · 186499 · 1512-PD39 = 1512 PD39 · BPD39 · 60A
Size: 3/4 mechanical seal = .750 mechanical seal = 19.05 mm seal · 1.275 x 0.281 seat · 0.875 working length = 0.875 operating height
Head type: N-11 seal = N11 seal · John Crane Type 21 = JC 21 = C21 · replaces the Type D / John Crane 2 head at the same working length and seat
Materials: BCDJF carbon ceramic nitrile · VCDJF carbon ceramic Viton / FKM · VLDLF SiC / SiC Viton / FKM
Other Sizes in the N LineThree N Line seals fit a 3/4 in. shaft. The seat is what separates them — measure yours before ordering.
Not the one? See all N Line / PS replacement seals or text a photo to 561-414-1046.