Gas Flow Control Valve

Paraflow – Flow Control Valve for operation of multiple vaporizers

  • Gas flow control valve
  • Prevent vaporizer over load in multiple installation


Solution to prevent overload of vaporizers

PARAFLOW is a very unique and useful valve that prevents the overload of vaporizers by limiting the gas flow to a constant value when multiple vaporizers are installed in parallel and operated simultaneously. It throttles the flow path inside its body according to the gas flow rate, and controls the flow so that it does not exceed the vaporization capacity of the vaporizer.

When operating multiple LPG vaporizers in parallel, there is a tendency for gas to be concentrated and consumed from the line with the lowest pressure loss among each vaporizer.
If an excessive amount of gas continues to flow from a specific vaporizer, it can eventually lead to overload, triggering the operation of the leakage prevention safety device and causing the vaporizer to stop.
And if one vaporizer is lost, the remaining vaporizers can also become overloaded, ultimately resulting in the interruption of gas supply.
This issue is particularly prone to occur when the distance varies between each vaporizer and the downstream gas supply piping.

Consider this case for example.
A gas user operating a factory with a peak gas consumption of 250 kg/h, equipped with a vaporizer rated at 300 kg/h.
Due to business expansion, the maximum gas consumption is expected to increase to 500 kg/h, prompting the user to consider upgrading the facilities.
While it is simpler to install a new vaporizer rated at 500 kg/h to replace the current 300 kg/h unit, the user wish to make use of the existing vaporizer. Therefore, instead of installing a new 500 kg/h vaporizer, the decision is to add another 300 kg/h vaporizer. By combining it with the existing 300 kg/h vaporizer, this will cover the increased gas consumption.

Image of installation with and without overload prevention

In this case, where a total of two 300 kg/h vaporizers are operated simultaneously, precautions need to be taken to address the risk of overload due to uneven flow (drift).
Paraflow is a solution to this.
The user can cover the increased consumption with these 2 units of 300kg/h vaporizers by having Paraflows on each vaporizer’s gas line.
In the event of gas consumption bias towards one vaporizer due to uneven flow, Paraflow controls the gas flow to ensure it does not exceed the vaporization capacity of the vaporizer, thereby preventing overload.

**In actual calculation, 20% safety margin should be in consideration when selecting vaporizers

Easy Introduction Movie on Kagla YouTube Channel :


Fluid LPG (Liquefied Petroleum Gas)
Corresponding vaporizer’s capacity 150kg/h 200kg/h 300kg/h 500kg/h
Operating flow rate *1 / *2 135kg/h 180kg/h 270kg/h 450kg/h
Design Pressure 0.05MPa
Design Temperature (℃) -5 ∼ +90
Inlet Pressure *3 For Propane 100% : 0.09MPa
For Butane 100% : 0.07MPa
Outlet Pressure *4 For Propane 100% : 0.07MPa ∼ 0.09MPa
For Butane 100% : 0.05MPa ∼ 0.07MPa
Inlet / Outlet Size 40A JIS10K Flange 65A JIS10K Flange
Inlet / Outlet Size 140 190
Weight (kg) 6 12
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  1. *1. By installing Paraflow, the gas flow rate will be reduced by 20%.
  2. *2. The values are when using the flow rate adjustment function(+10%).
    When using the flow rate adjustment function, please carefully read the precautions listed in “About using the flow rate adjustment function” in this manual.
    The operating flow rate may vary depending on installation conditions and other factors.
  3. *3. When using propane/butane mixed gas, please refer to “Setting of Inlet Pressure” in this manual.
  4. *4. With propane, for example, when the gas flow reaches the operating flow rate, the outlet pressure will drop from 0.09 to 0.07MPa.

** For small vaporizers with capacity of 50-100kg/h, we have related product “FL Valve”. Please contact us for details.

Sample installation image

Installation image of PARAFLOW for simultaneous operation of multiple vaporizers

Installation image of PARAFLOW for natural vaporization back up when consumption increase

Product Link-1: Space saving product Kagla PUREFLOW – Ball valve with built-in Strainer (*1)

Product Link-2: Medium pressure regulator Kagla KR series

Product Link-3: Electric water bath vaporizer Kagla AX5 series

Product Link-4: Electric water bath vaporizer Kagla CX series


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