1. Start with what "low pressure" means for your project

People use the phrase "low pressure" for different jobs. Some buyers need a regulator that takes medium-pressure gas and delivers it to burners at a moderate outlet pressure. Others need a final stage at only a few kPa. These are different selection problems, so they lead to different quotes.

According to the published product data, the RTJ2-/GK series is used for pressure regulation and stabilization for high and medium pressure gas users, industrial furnaces and other industrial and commercial burners in urban gas pipeline networks. Its documented ranges are:

• Inlet pressure (P1): 0.1–0.8 MPa
• Outlet pressure (P2): 50–400 kPa

If your target outlet pressure falls in the 50–400 kPa range, the GK series is a reasonable candidate. If you need an outlet in the 1–30 kPa range, see Section 6.

2. Specification checklist for the RTJ2-/GK series

Note on the closing pressure grade: The source material gives two different values: SG15 in the performance description and SG20 in the technical parameter list. If the closing pressure grade affects your design or acceptance criteria, ask for the confirmed value in writing before you compare quotes.

The product description also mentions a cut-off valve with what the manufacturer calls a fifth-generation, trip-release cut-off mechanism. It also says the regulator can be maintained online and has few accessories.

3. Match size to flow at your actual inlet pressure

Flow capacity changes with inlet pressure, so choose the DN size from the published flow table at your real operating inlet pressure, not just at the maximum. Here are selected values from the source table for an outlet pressure of 0.05–0.4 MPa:

The source table does not give the flow unit or reference conditions. Ask the supplier to confirm them before you use these figures to size the regulator. If you buy a valve that is too large or too small, a lower unit price does not save you money.

4. Check installation dimensions

Face-to-face length and overall dimensions affect how the regulator fits into your skid, cabinet or pipe run. The published dimension table lists:

Ask for a dimensioned drawing that shows what A, B and C refer to, and check it against your layout.

5. What to send with a price request

To get a useful quote for a gas pressure regulator, send the following:

1. Gas medium (and confirmation that it is non-corrosive)
2. Minimum and maximum inlet pressure
3. Required outlet set pressure
4. Required flow at minimum inlet pressure, with the unit
5. Ambient and gas temperature range
6. Required nominal size and flange standard/pressure class
7. Any required accuracy or closing pressure grade
8. Required documents, standards or certifications for your market (confirm these with the supplier; this article does not claim any)

If you send the same requirements to every supplier, you can compare the quotes fairly.

6. When the GK series is not the right choice

The GK series is not specified for very low outlet pressures. Its outlet range starts at 50 kPa. Its working temperature range, -20 °C to +60 °C, does not cover colder service. Its connection is PN1.6 MPa flanges to HG/T20592-2009. It is also not specified for corrosive gases.

If you need a lower outlet pressure, these documented series from the same catalog list lower ranges:

• **RTZ1-/FQ Series:** a direct-acting regulator for residential areas, small industrial and commercial users and small direct-fired equipment. Inlet 0.02–0.6 MPa, outlet 1–30 kPa, DN25–DN80, with an overpressure cut-off device.
• **RTZ1-/NQ Series:** for civil-area gas, gas boilers and large furnaces. Inlet 0.01–0.6 MPa, outlet 1–30 kPa, DN50–DN200, with an overpressure safety cut-off device.
• RTZ1-50/0.4(0.8)E(K)Q Series: DN50, inlet 0.02–0.4 (0.8) MPa, outlet 1–30 kPa or 30–150 kPa. It has a built-in overpressure safety cut-off and a built-in safety relief device.

Each of these needs its own check against your pressures and flow before you ask for a quote.

Summary

For a buyer researching low pressure gas regulator price, the RTJ2-/GK Series Gas Pressure Regulator fits applications that reduce 0.1–0.8 MPa inlet gas to a 50–400 kPa outlet for industrial and commercial burners and furnaces, in sizes DN50 to DN200. First confirm the closing pressure grade, the flow units and your market's documentation requirements. Then compare prices on a like-for-like basis.