Kunkle 6221 Safety Relief Valve — 1″ NPT, F Orifice (Steam ASME Section I, Teflon PFA Seat)
SKU: KUN-6221-FT-A-1
The Kunkle 6221 is an oversized-outlet, full-nozzle bronze safety relief valve with a Teflon (PFA) disc insert, for steam service only. This 1″ NPT inlet variant — F orifice, 0.336 in² — is available across a 15–250 PSI set pressure range for Steam ASME Section I service, carrying ASME Section I (V stamp), National Board Certified. The PFA disc provides tight, leak-free shutoff for steam applications. Body: bronze (BRZ B584-C84400); oversized side outlet (1-1/2″) with dual control rings for precise blowdown adjustment. Specify your required set pressure when requesting a quote.
Specifications
| Body Material | Bronze (BRZ B584-C84400) |
| Trim Material | Brass (BRS B283-C48500), Teflon (PFA) disc insert |
| Inlet Size | 1" NPT |
| Outlet Size | 1-1/2" NPT |
| Outlet Configuration | Oversized side outlet |
| Orifice Designation | F |
| Orifice Area | 0.336 in² |
| Set Pressure | 15–250 PSI |
| Temperature Range | Per PFA seat — contact for rating |
| Capacity — Steam I | 482–4136 |
| Flow Coefficient | 0.878 |
| Service Media | Steam |
| ASME Certification | ASME Section I (V stamp), National Board Certified |
| National Board Certified | Yes |
| Seat Type | Teflon (PFA) |
| Weight | 3-3/4 lb |
| Overall Height | 8-1/2 in |
Need a quote or have a technical question?
Call (324) 888-1524 or submit a quote request online. Requests received before 3 PM ET are typically quoted the same business day.
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