Issues with connecting the EJA transmitter to the three-valve manifold
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Hello, everyone who is into the sea. There’s a problem that has been bothering me, and I’m hoping you can help me out. Thank you! When connecting the EJA110 and EJA430 transmitters with the corresponding two-valve, three-valve, and five-valve assemblies, the EJA selection catalog lists only 1/4NPT and 1/2NPT connections. However, the fixing bolts provided by the valve assembly manufacturers are of type UNF7/16-20 or M10*1.5. It’s not possible to connect the transmitters to these valve assemblies since the dimensions do not match; therefore, it is necessary for either the manufacturer to provide non-standard fittings or adapters. (For example, three-valve and five-valve assemblies have four bolt holes for connection to the transmitters, while two-valve assemblies have two such bolt holes.) I hope experts will respond promptly – thank you!
1/4NPT and 1/2NPT are the thread sizes for connecting pressure tap fittings; they are not the thread sizes for fixed process connections or three-valve assemblies.
The screws for the three-valve assembly should be in the box, usually included with the manufacturer’s supply
There should also be pipe fittings and a short section of pipe between the valve assembly and the transmitter; the diameter can be changed using pipe fitting components in this section
Is it that complicated? Does an integrated valve assembly still require an intermediate connecting part? Deceiving the young!
As a supplementary question, if it’s 1/2 NPT threads on the high and low voltage sides, how is sealing achieved? The body comes standard with 1/4NPT (F) threads, which allows for sealing using O-ring PTFE gaskets!
1. Two-valve assemblies, three-valve assemblies, and five-valve assemblies are supplied together with the transmitter and installed as a single unit; however, there is a gasket between the valve assembly and the transmitter, and they are fixed to each other using bolts. 2. How to connect the valve assembly to the pressure tap pipes: The pressure tap ports of the valve assembly are usually 1/4NPT or 1/2NPT, and a fitting is typically provided for this purpose. The specifications for such fittings are, for example, 1/2NPT-Φ14 – one end has 1/2NPT threads while the other end is a Φ14 stub; the fitting contains a swivel joint that can be removed from the middle, and there is a gasket inside the swivel joint, all of which come as part of a complete set. One end is 1/2NPT and connects to the valve assembly – it can be screwed in directly; if that doesn’t work, a gasket can be used, but tape should not be applied, as NPT threads have excellent sealing properties and can withstand high pressure levels. The other end is Φ14, which is actually a short tube with an outer diameter of 14 mm, and it is welded directly to the Φ14 pressure lead tube. 3. If no valve assembly is used, the process interface of the transmitter is 1/2 NPT or 1/4 NPT; it simply lacks a valve assembly, but the connector remains exactly the same and the requirements are identical.
One end is 1/2NPT and connects to the valve assembly; it can be screwed in directly, with no need for gaskets or tape, as the NPT thread provides excellent sealing properties and can withstand high pressure levels.
Has the original poster never seen the actual item? It is recommended to find a set of transmitters, a three-valve assembly, compression fittings, 1/4 inch fittings, 1/2 inch fittings, as well as the necessary mounting bolts; once you take a look, you’ll understand. Just follow instructions, but the more you do that, the more confused you become!
Why does LZ need to purchase the valve assembly and the transmitter separately? When purchasing the transmitter, just specify that it should come with the corresponding valve assembly. I once bought them separately, only to find that they didn’t match, so I had to replace them again, which was quite troublesome. If you are buying spare parts, it’s best to purchase them according to the specifications of the valve assembly that comes with the transmitter, so as to avoid mistakes.