Technical specifications:
| Type: | Differential bypass, safety relief |
| Model: | MLB-20 |
| Media: | LPG (propane, butane, propane-butane blends) |
| Working pressure: | up to 1.8 MPa (18 bar) |
| Pressure differential: | 0.3 MPa (3 bar), adjustable |
| Flow rate: | 5–50 L/min |
| Connection: | 3/4" (G3/4 BSP), female thread |
| Body material: | Brass |
| Stem guide bushing: | Brass (NOT PTFE — no jamming) |
| Sealing: | NBR (nitrile rubber) |
| Temperature range: | -35 °C ... +55 °C |
| Warranty: | 12 months |
LPG Differential Bypass Valve for Gas Dispensers
The MLB-20 differential (bypass) valve maintains a constant pressure differential between the supply and return lines of liquefied petroleum gas (LPG — propane, butane, propane-butane blends) in LPG dispensers and at automotive LPG refuelling stations. It is a key component of the dispenser's hydraulic circuit — without it, reliable operation of the piston meter, gear pump, and dispensing nozzle is impossible.
Purpose
- Pressure stabilisation. The valve relieves excess gas from the supply line back into the tank via the return line, holding the pressure differential at the preset value (default 0.3 MPa).
- Piston meter protection. Prevents water hammer effects when the nozzle closes abruptly — the valve opens instantly to relieve the surge.
- Pump overheating protection. When the nozzle is closed, the valve maintains gas circulation through the pump, preventing dry running and cavitation.
- Liquid phase preservation. Continuous circulation and back-pressure ensure the liquefied gas does not flash to vapour — metering stays in the liquid phase.
⚡ Key advantage over budget alternatives — solid brass internals
Important: in this model the body, the moving stem, and the guide bushing are all made of brass. Most low-cost Chinese clones use PTFE (fluoroplastic) as the stem guide — a plastic that, under LPG pressure swings and the temperature cycles of an outdoor LPG dispenser, deforms, swells, and jams. A jammed differential valve means either the dispenser can no longer release fuel (stuck closed) or it loses back-pressure and miscounts the volume (stuck open).
Over years supplying LPG dispensers to refuelling stations across Ukraine, NPF Gerkon has repeatedly encountered jammed PTFE-guided clones in the field. We deliberately source the solid-brass variant of MLB-20 — a choice validated by long-term operation and feedback from our customers.
Real-world benefits:
- Stable operation without sticking across the dispenser's service life
- Resistant to outdoor temperature cycling (winter/summer)
- Linear trip characteristic — accurate fiscal LPG metering
- No need to replace the valve every season
Design
- Solid brass body, stem, and guide bushing — no PTFE in the moving pair
- Poppet valve element with stainless steel spring
- Adjusting screw for setting the trip threshold
- 3/4" (G3/4 BSP) threaded connection — standard for LPG dispensers
- NBR sealing — petroleum and oil resistant rubber
Applications
- LPG dispensers at automotive LPG refuelling stations
- LPG metering skids at oil terminals and depots
- Stationary and mobile LPG refuelling installations
- Reverse-flow LPG transfer units
Warranty and Support
12-month manufacturer warranty. NPF Gerkon Ltd provides consultation on valve selection for specific dispenser characteristics (pump capacity, working pressure, piping schematic) as well as technical support during installation and commissioning.
SHIPPING INFORMATION FOR UKRAINE
Our company is committed to fast shipping and delivery throughout Ukraine. We work with carriers that offer the best balance of price and quality, including:
NOVA POSHTA
1-3 days. Delivery speed depends on your location. After placing your order and payment, we ship the same day or the next.
SAT
Delivery time 3-5 days. Speed depends on the distance between sender and recipient. This is the most economical option compared to Nova Poshta.
DELIVERY
Shipping takes 4-7 days. This is the slowest method, but its advantage is the low cost.
FREIGHT POOLING
Shipping is done via shared transport through a dispatcher. Finding a vehicle takes 1-2 days; speed depends on the destination (major cities are faster, remote villages slower). This method is cheaper than the carriers listed above.
We work throughout Ukraine, and on request can arrange delivery via another courier service not on our list.
After placing your order in our online store, please provide the following information for delivery to your region:
- Recipient's full name
- City or town
- Number of the nearest warehouse (if shipping via courier services)
- Mobile phone number
Once the goods are shipped, we will provide you with the waybill number. When picking up your order, please bring your passport and the waybill number.
NOTES:
- The seller is not responsible for the operation of postal / courier services.
- Shipments are insured for full value; in case of damage the carrier is obligated to compensate you in full.
- Shipping costs are paid by the buyer (or by mutual agreement).
- If the requested product cannot be supplied, an equivalent replacement will be offered upon your approval.
If you couldn't find an answer to your question in this section, please contact us for more detailed information.
PAYMENT METHODS
After placing an order for a selected product in our store, we verify stock availability and confirm with you. Payment can then be made using one of the following methods:
- Bank transfer to the company account (VAT included).
- Cash on delivery (payment upon receipt).
Before paying via bank transfer, please contact us to confirm product availability.
Cash on delivery is processed at the carrier's warehouse. The service fee is 2% of the total + 15 UAH for payment processing. For an order of 1000 UAH you will pay 35 UAH for this service plus the shipping cost.
The second method is more reliable as you can inspect the goods on the spot, but it is also more expensive, so before paying you may want to consider which method suits you best.
If payment is received by 12:00, we ship the same day; if payment arrives later, shipping is processed the next day.
For any questions about payment, please contact us — if you haven't found an answer to your question, we will provide more detailed information.
WARRANTY & SERVICE
- Warranty on Gerkon fuel dispensers — 18 months;
- Warranty on Gerkon measuring tanks — 18 months;
- Warranty on level meters — 36 months;
- Warranty on fuel dispenser connection installation — 18 months;
The manufacturer guarantees free replacement or repair of dispenser parts and assemblies that fail due to manufacturing defects, provided that transportation, storage, and operation rules are observed.
