NPT vs BSPT vs BSPP for Titanium Threaded Fittings
NPT, BSPT and BSPP descriptions are not interchangeable. A buyer must state the exact thread system, size, gender and sealing method at every port. Similar nominal sizes do not guarantee compatible thread angle, pitch, taper or sealing behavior.
Quick Comparison
| Thread | General form | Typical sealing concept | Reference |
|---|---|---|---|
| NPT | Tapered pipe thread | Thread interference with approved sealant where required | ASME B1.20.1 when invoked |
| BSPT | Tapered pressure-tight pipe-thread family | Pressure-tight joint made on threads under the specified system | ISO 7-1 where invoked |
| BSPP | Parallel fastening pipe thread | Separate sealing surfaces and seal are required for pressure-tight assembly | ISO 228-1 where invoked |
Why Mixing Threads Is Unsafe
Forcing unlike threads together can produce limited engagement, damaged flanks, misleading torque and an unreliable seal. Titanium also requires an approved assembly and anti-galling procedure. The mating component and gage basis must be defined before manufacturing.
RFQ Data for Every Port
- Thread system and complete designation
- Nominal size and male or female form
- Tapered or parallel requirement
- Applicable standard and edition
- Gaging and inspection requirement
- Sealing face, gasket or approved sealant
- Mating component material and geometry
Apply this definition to every port on a titanium threaded tee, both ends of an elbow, and every component of a union.
Avoid Ordering by Trade Name Alone
Send the fitting drawing, thread designation, mating-part data and service conditions with your inquiry for Titanium Threaded Fittings.
Related Technical Reading
Titanium Threaded Fitting Types · Titanium Threaded Fitting Applications · Grade 2 vs Grade 7 vs Grade 12 Fittings · Preventing Titanium Thread Galling
Frequently Asked Questions
Can NPT and BSPT threads be connected because both are tapered?
No. Their thread forms, pitch series and dimensional conventions differ. A connection that starts to engage is not proof of compatibility or sealing performance. Specify the exact thread standard for both mating ports.
Does BSPP seal on the threads?
BSPP is a parallel thread system and commonly relies on a separate sealing arrangement such as a bonded seal, gasket, O-ring or defined sealing face. The fitting and port design must identify the intended seal.
What must be included on a threaded fitting drawing or RFQ?
State NPT, BSPT or BSPP; nominal size; male or female; applicable standard; pressure and temperature basis; sealing method; titanium grade; fitting geometry; surface condition; inspection and documentation.