Before you do this you must create the gas as a product in the product database.
Go to Products > New
Select "f-gas" in the item type box.
Next, create a PO by going to Purchases > Purchase orders > New.
Fill in the PO and add the refrigerant you require. Qty is "kg" in this case for the refrigerant needed.
Once you’ve saved the PO, you can now book it in via goods inwards.
Go to Purchases > Goods Inward > Process Goods Inward.
Type the PO number in the find PO box, to find the PO assigned to the refrigerant.
Next, put the amount of kg of refrigerant you have been given in the 'Received today' column, then go to the 'Location' column and select the cylinder the refrigerant is going to.
Click 'Process goods received' and the transaction will then appear in goods inward.