Hiwi Double stage Pressure regulator + SV & CV

This high-quality pressure regulator is used to reduce the pressure of approx. 54 bar within the gas cylinder to a working pressure of approx. 1 to 3 bar (maximum working pressure 3 bar). By combining the working pressure manometer and the cylinder pressure manometer you can regulate the CO₂ supply very precisely and you know at once when it is time to refill the cylinder. The integrated fine needle valve allows a very precise regulation of the CO₂ supply for the aquarium. Thanks to the double chamber system, the working pressure remains constant until the cylinder is completely empty.

When pressure regulators without a double chamber system are used the working pressure may rise relatively fast and abruptly as soon as the gas filling inside the bottle goes below around 20% of the nominal filling quantity. If you do not re-adjust manually in such a case, the amount of CO₂ supplied to the tank will increase significantly and surmount the dosage that was originally set. If you do not want to take on this task, the remaining 20% of CO₂ would need constant adjustments of the working pressure.

With this double-chamber pressure regulator, on the other hand, the cylinder can be emptied almost entirely without the need to adjust the working pressure for the last 20% of CO₂, which is of advantage especially when you use large CO₂ cylinders. In a 10 kg cylinder, e.g., around 2 kg of CO₂ would need constant adjustments regarding the working pressure.

A bubble counter is also included in the scope of delivery, which can be screwed directly onto the pressure regulator if desired. The procedure is described in detail in the linked instructions.

Please keep in mind that all components of the pressure reducer have been glued together by the manufacturer. These can not be unscrewed without damaging them. If the needle valve is removed, the manufacturer's liability will expire prematurely. The hose connection on the fine needle valve is an exception. This is not glued in due to the fine thread, so that in the event of a defect, it is not necessary to replace the entire fine needle valve but only the hose connection. The union nut on the needle valve can also be removed if necessary to mount the included bubble counter.

This pressure regulator from Hiwi is also available without solenoid valve (SV) and check valve (CV): Hiwi Double Stage Pressure Regulator

In addition to the Double Stage Pressure Regulator, a version with one pressure chamber is also available, which can be used for pure plant aquariums: Hiwi Pressure regulator + SV & CV

• The pressure regulator is designed for returnable cylinders
• Thread: W21,8 x 14G
• The thread is the standard in Europe, the United Kingdom (UK) and Taiwan (BS341 / DIN477 / W21.8)
• Seal included
• The connection for the CO₂ tubing is equipped with a metric thread (M6)
• Bubble counter included and can be installed if required
• High-quality solenoid valve with low energy consumption. The solenoid valve is firmly attached to the pressure regulator.
• 1.5 m power supply cord with Schuko plug
• Power supply: 230 V AC; 50/60 Hz; 1.6 VA open
• Closed when without current
• 100 % ED (suitable for continuous operation)
• Permissible temperature: -30 to +130 °C
• Max. ambient temperature: 40 °C
• Protection class IP65 (dust-proof and protected against jets of water)
• Insulation class F (155 °C) screwed to plug
• Max. pressure difference when operating the solenoid valve: 16 bar
• A check valve secures the entire CO₂ system and is permanently installed with the solenoid valve and pressure regulator
• With German instructions of use
• Suitable replacement seal Hiwi seal hard

Please use the pressure reducer only after reading the operating instructions, which are linked above. There are two different designs of the Hiwi dual-stage pressure regulator: While the gas cylinder is always positioned upright, the pressure gauges either point upwards with side-facing scales or to the side with upward-facing scales, depending on the model. The functionality of the pressure regulator remains fully intact in both cases.

• Make sure that you really start the pressure reducer with a CO₂ cylinder.
• Turn the working pressure adjustment screw (operating instructions 7) counterclockwise.
• Close the fine needle valve (operating instructions 5.1) by turning it clockwise. CAUTION: Tighten only slightly!
• Position the pressure reducer so that the pressure gauges are facing upwards.
• Fasten and tighten the pressure reducer to the CO₂ cylinder using the union nut (operating instructions 3).
• It is essential to ensure that the seal is correctly seated and that the sealing surfaces are clean. If the seal is damaged or lost, please replace it.

The Hiwi Fixed spanner 30 mm is most suitable for the installation.