NPT Adaptors is one most popular hydraulic pressure station equipment fittings in the CNC lathe and injection molding machines marketplace, All NPT adapters are machined with American National Standard Pipe thread so called the NPT style fittings to connect oil port. Jiayuan fittings offer a series of NPT Nipples, NPT plug, NPT caps, NPT Couplings, NPT conversion reducer, expanders and adapters to mate with this NPT end connections, body shape as Straight adapters, Elbow Adapters, Tee adapters,Adjustable adapters etc.
NPT taper thread fittings is commonly used in industrial applications, it is the basic metal to metal sealing design for a seal.NPT threads, when assembled without a sealant, leave a spiral leak path at the crest-root junction as shown in Fig. F1. To seal pressurized fluid, NPT threads require a suitable sealant.
Fig. F1 — NPT: Wrench Tight, No Crest-Root Contact, Flank Contact Only
Thread NPT standard is ANSI B1.20.1, FED-STD-H28/7
Thread NPTF standard is SAE J476, ANSI B1.20.3, FED-STD-H28/8
NPTF threads (Dryseal), on the other hand, when assembled, do not leave the spiral leak path. This is because they have controlled truncation at the crest and root, ensuring metal-to-metal crest-root contact prior to, or just as the male-female thread flanks make contact as seen in Fig. F2. Upon further tightening, the thread crests are flattened out until the flanks also make metal-to-metal contact as seen in Fig. F3. Thus, theoretically at least, there is no passage left for the fluid to leak, provided all surfaces are flawless and dimensions exact. In reality, this is not the case and a sealant/lubricant is necessary to achieve a leak free joint, even with NPTF threads. The sealant/lubricant fills all imperfections in the surfaces affecting the seal and also provides lubrication to ease assembly and minimize galling.