FAQ – Frequently asked questions
On this page you will find a collection of frequently asked questions from customers about industrial gases and the most common problems they have encountered.
If you can’t find the answer to your question here, please contact our customer service team and we’ll get back to you as soon as possible:
asiakaspalvelu@woikoski.fi or 040 166 2023
Leaking gas cylinder
If the cylinder is leaking, turn off the cylinder valve and remove the pressure regulator (colloquially also known as a “pressure reducer”). If the leak stops, the leak is between the pressure regulator and the cylinder valve.
- Check the seal: it is a good idea to change the seal when replacing the bottle. The black rubber O-ring in particular will wear/brittle over time and can cause a leak. Check that there are no two seals on top of each other. Remove the excess gasket.
- The seal can be damaged if the pressure regulator is tightened too much. Do not use force when tightening. The circular pressure regulator is tightened by finger force, without tools. An angled pressure regulator is tightened first to finger tightness and then about a quarter turn with a wrench.
If replacing the gasket does not help, the problem is probably with the pressure regulator. See if replacing the pressure regulator solves the problem. The pressure regulator is affected by temperature and, if stored in cold conditions, it will easily fail. Pay attention to the storage of the pressure regulator and store it at room temperature!
If the leak continues after the pressure regulator is removed and the cylinder valve is closed, the leak is in the cylinder.
- Move the bottle to as safe a place as possible (e.g. outside). Do not use a leaking cylinder, but allow it to empty.
- If the leak is clear and it is a flammable gas (hydrogen, acetylene, LPG), call the emergency number. NOTE! Do not go near the leaking gas with a phone.
The bottle valve is opened by turning the valve counterclockwise by no more than one turn. No tools may be used to open the valve. If the valve cannot be opened by hand, the bottle must be replaced. If the valve does not open, it may also be turned “over-open”, in which case the valve will not open any further. Make sure that the valve is not “over-opened” by turning the valve clockwise.
Disposal of a cylinder
Cylinders rented from Woikoski Oy have the words Woikoski or AWO stamped on the neck of the cylinder. Woikoski accepts cylinders marked with these stampings and can deliver them to Woikoski dealers. Find your nearest reseller here.
Distributors can arrange for bottles for disposal to be collected. For more information, please contact our customer service asiakaspalvelu@woikoski.fi or 040 166 2023.
Private individuals can take their own bottles to a municipal waste station. Business customers are responsible for disposing of their cylinders themselves. Finnkoritus Oy is Woikoski’s partner for the disposal of gas cylinders. They can be contacted directly for all matters relating to the disposal of gas cylinders.
Finnkoritus Oy, Bodomintie 31, 02940 Espoo, tel. +358 9 855 7109, www.finnkoritus.fi. Please note that Finnkoritus does not accept cylinders containing toxic gases or LPG cylinders.
For further information, please contact Woikoski’s customer service on 040 166 2023 or asiakaspalvelu@woikoski.fi
Replacing the proprietary bottle with a rental bottle
- Customer cylinders can be exchanged for a free rental period, in which case the customer only pays the price of the gas for the rental cylinder. No financial refunds will be made for the cylinders. The rental period to be credited varies depending on the inspection, type and condition of the cylinder, among other things. The exchange takes place at a Woikoski retail outlet. Find your nearest reseller: Resellers
- Direct delivery customer: contact our customer service.
- Note! No refund for cylinders with round bases/leg irons or 150 bar.
- For more information, please contact our customer service: asiakaspalvelu@woikoski.fi and 040 166 2023
Small bottle or pack, pressure less than 200 bar
Take the bottle or pack inside in time to warm up, as it can take up to a day to warm up. The gas pressure varies with temperature: 200 bar at 15°C and decreases at freezing temperatures.
If you did not order a connection, you will have to open the cylinder valves of the packs yourself. Only in the case of carbon dioxide packs are they pre-opened.
Please note that carbon dioxide and nitrous oxide are in liquid form in the cylinder, so that the pressure of a full cylinder is about 50 bar at 15 °C. For this reason, the gas volume can only be checked on the scale. The neck of the bottle is marked with the tare weight (kg) and the filling volume (kg) of the bottle, which allows you to calculate how much CO2/liquid gas is in the bottle.
Please note that the acetylene cylinders contain a porous mass inside, as well as liquid acetone absorbed into the mass, into which the gaseous acetylene is dissolved. For this reason, the quantity of acetylene can only be checked on the scale. The neck of the bottle is marked with the tare weight (kg) and the filling volume (kg), which allow you to calculate how much acetylene is in the bottle. The pressure of acetylene is about 18 bar at 15 °C.
Dewar
Possible cause and action
- Usage has been low: If gas consumption is less than approx. 3 m³/day, the Dewar pressure will rise. Using gas lowers the pressure, and pressure can also be reduced by releasing gas through the vent valve, if the environment allows.
- Pressure build-up valve is open: If it is a low-pressure Dewar, check that the valve is open.
- Vacuum insulation is damaged: Damage to the vacuum insulation may cause a frozen spot on the tank wall or “sweating” on the tank surface.
Possible cause and action
- Pressure build-up valve is closed: If the pressure is not at the desired level, open the pressure build-up valve.
- Usage has been too high: Pressure drops if gas is used faster than the Dewar can supply.
- Gas is leaking: Do you hear a hissing sound or see ice forming at a leak point? A leaking Dewar should be moved to a safe location (e.g., outdoors) if it can be done safely. Contact Woikoski customer service.
Possible cause and action
- Normal operation or fault: Determine whether the hissing is normal operation or a leak. Ensure shut-off valves are properly closed.
- Pressure relief valve is open: If pressure is high, the relief valve releases gas, causing a hissing sound.
- Tank is leaking: A leak typically occurs at a connection point. Try to locate the leak. Move the leaking Dewar to a safe location (e.g., outdoors) if possible. Contact Woikoski customer service.
Possible cause and action
- Structures have cooled: Frost or ice forms on cooled surfaces during use.
- Pressure build-up valve is open: Using the pressure build-up valve creates an ice ring around the lower part of the tank.
- Vacuum insulation is damaged: Damage may cause a frozen spot or “sweating” on the tank wall.
- Cold gas is escaping: If cold gas escapes, ice usually forms at the point. Listen for hissing sounds.
Propane / LPG
In a residential apartment, boat, motorhome or caravan up to 25 kg. In practice, this means two 11 kg bottles.
As LPG is an odourless and colourless gas, a fragrance (tetrahydrothiophene) has been added for safety.
The composite bottle is transparent, so it is easy to check the amount of gas. The steel cylinder must be weighed. The tare weight of the casing is marked on the shoulder of the bottle and, when subtracted from the total weight of the bottle, the gas content remains.
Do not store or transport the LPG cylinder horizontally. If the cylinder is in a horizontal position, the gas may come out as a liquid and the safety valve may be compromised. If the cylinder has been stored in a horizontal position, place the cylinder in an upright position and try again in a moment.
Make sure that you have a threaded LPG cylinder, NOT a red-collar threaded cylinder with a threaded valve, from which the gas comes as a liquid thanks to the riser.
The valve may freeze if there has been water between the valve and the pressure regulator. Check whether the pressure regulator is properly attached to the bottle, whether the bottle is leaking from the valve or between the pressure regulator and the valve. These may be symptoms of freezing.
Action: close the bottle, disconnect the pressure regulator and wait for the valve to melt. Dry the joints and try again.
- Unscrew the plastic protective cap on top of the valve
- All LPG cylinders with a screw valve outlet are fitted with a protective nut after filling, using a pneumatic tool, which is intended to be gas-tight even if the cylinder valve is accidentally opened. A wrench may be required to remove the guard.
- NOTE! LPG cylinders have left-hand threaded valves (as for other flammable gases)
If no gas comes out of the cylinder, the cause may be:
- The valve is broken. Action: return the bottle to Woikoski
- The pressure regulator is broken. Action: replace the pressure regulator
- The bottle is empty (can be checked on the scale: the tare weight of the bottle is marked on the bottle, which is subtracted from the scale reading = bottle content) Action: replace the bottle with a full one.
If the gas supply from the LPG cylinder stops in the middle of use, this may be due to one of the following:
- The bottle is empty. The bottle is marked with the tare weight of the cork, so you can check the fullness of the bottle on the scales.
- The gas has been used too long in freezing winter temperatures and the liquid no longer evaporates.
- Vaporisation can also stop if the gas has been used at a very high flow rate for a long period of time. In this case, the liquid cools down and no longer vaporises.
Problems with threaded valves can also apply to pressure valve cylinders. The most common cause of a cylinder not producing gas is an inappropriate pressure regulator. If the pressure regulator does not fit the cylinder properly, the needle valve on the cylinder does not open and no gas comes out of the cylinder, try a pressure regulator from another manufacturer.
Pressure valve cylinders have a needle valve that the pressure regulator opens when it is attached to the cylinder. The bottle is also filled through the same valve and then passes through a “sniffer” to ensure that the valve does not leak. Bottle valves are very carefully sized due to the strict legislation and regulations that apply to LPG cylinders.
According to extensive surveys of the LPG industry, the problem is the plastic body construction used in some pressure regulators, where the regulator needle does not open the valve needle sufficiently. In general, the regulator works better when new, but in use it becomes loose. High temperatures also play a role, as they increase the pressure. No fault has been found with the LPG cylinders or valves themselves, despite investigations.
Also pay attention to the storage of the pressure regulator: store at room temperature! The regulator’s operation is affected by temperature. If the pressure regulator is stored in the cold, it will easily fail.
It is also possible that the cylinder valve has been dented and the pressure regulator is not properly attached. In this case, replace the bottle with a new one.
Acetylene
- If the acetylene bottle has been held horizontally during transport, keep the bottle upright for 24 hours before use.
- If the liquid still comes out, return the bottle to Woikoski
- If liquid comes out of the straws, disconnect the hoses, straws and backflow preventers and allow the liquid to evaporate. The liquid will not destroy the equipment; after the gas has evaporated, they will be in working order.
If the black substance is clearly coming from inside the bottle, there has probably been a fire in the bottle. Return the bottle to Woikoski for inspection.
There are basically two types of standard valve guards used on gas cylinders:
The open valve covers are attached to the cylinder at all times and must not under any circumstances be removed from the cylinder itself.
A sealing knob that is removed from the valve for the duration of the gas operation when the cylinder is attached to the dispenser (cart). The dome is safer during transport because it protects the valve during transport and there is no risk of the valve opening during transport.
- Woikoski’s acetylene bottles are fitted with a stopcock, because an open valve guard would change the tare weight of the bottle and cause problems during filling, which is done on a scale. In addition, an acetylene cylinder with an open valve guard would run the risk of the valve opening during transport as a result of a bump caused by the valve guard of another cylinder.
- When storing or transporting the cylinder, the protective hood must be in place. When the cylinder is in use, the valve guard does not need to be in place, but the cylinder must be secured so that it cannot fall over. When the cylinder is attached to the cylinder trolley, it is considered to be attached to a rack that prevents it from tipping over.
Balloon helium
The filling device is screwed onto the bottle valve by hand. Then the bottle valve is opened about half a turn and the filling device is turned up or down, so that gas starts to flow. When the filler is released, the gas flow stops and the filler returns to the horizontal position.
If the balloon helium filler is leaking between the valve and the filler:
If there is a leak between the filling device and the valve, contact our customer service to replace the bottle with a new one.
Check that the filling device has an O-ring seal. If there is no seal, insert a 10 mm O-ring and tighten by hand (do not use tools).
Liquid nitrogen canister
Nitrogen canister with dispenser
- You may hear a hissing sound coming from the jug relief valve when excessive pressure is released through the relief valve. The sound is perfectly normal.
Nitrogen canister with breathable cap
- The cap lets the pressure inside the jug escape without making a hissing sound. If the jug hisses, the vacuum in the container is probably weak and the jug should be returned to Woikoski for service.
- The liquid nitrogen in the nitrogen can boils, i.e. slowly gasifies, despite the vacuum insulation of the can.
- Nitrogen retention time is affected by the storage temperature of the jug and how often the jug is opened. An empty jug will heat up, causing the nitrogen to evaporate faster, so don’t let the jug empty.
Food industry gases
The oxygen in the air triggers the growth of typical food spoilage aerobic microbes. In general, mixtures of carbon dioxide and nitrogen used as a protective gas reduce the potential for microbial growth. It should be remembered, however, that only an unbroken cold chain will ensure that the desired quality is maintained.
Dry ice
Dry ice will keep for about a week in its unopened box. We guarantee this shelf life only in the box in which we have delivered the product.
Dry ice can be ordered from Woikoski dealers or directly from the order service: tilaukset@woikoski.fi or 040 166 2023. Orders must be placed at least two working days before the desired delivery date by 12 noon. If you need dry ice for the weekend, order delivery for Friday. Delivery will be made by Post. Dry ice orders are paid by invoice after delivery, so you must have customer details set up in our system. Read more in the instructions: dry ice ordering instructions (PDF).
Periodic inspection of gas cylinders
The cylinder is checked regularly to ensure that it is as safe as possible to use. The cylinders undergo a detailed check with test pressures. The next inspection date is marked with a sticker on the shoulder of the cylinder.
For most gases, the inspection interval for cylinders is 10 years. For toxic and corrosive gases it is 3 or 5 years.
A periodic inspection, i.e. an inspection, is a statutory periodic inspection of pressure equipment. Periodic inspection and testing of reusable pressure receptacles must be carried out by an approved body (Ministry of Transport and Communications Decree 171/2009, section 6.2.1.6).
If the cylinder has not been used for e.g. 5 years but the inspection is valid, the cylinder and the gas can be used normally. Gases do not expire (except for food, speciality and medical gases, the expiry date is indicated on the label of the cylinder).
If the inspection has expired, the bottle can be safely used up and brought empty to the inspection as soon as possible.
According to the law, the cylinder may be used and transported under pressure for one year after the expiry of the inspection period. After this period, the cylinder must be depressurised and submitted for inspection.
- Round bottom bottles
- Bottles with footplate
- Foreign bottles missing the π-mark.
- A bottle that has been in a fire or otherwise damaged. In doubtful cases, the bottles may be sent to a surveyor who will inspect the bottles and, if necessary, make a rejection decision.
- Diving breathing apparatus bottles
- 150 bar customer cylinders
- Ambiguities in the bottle (bottle approval, incomplete labelling, etc.)
- Bottles with a different valve than the one used in Finland. For these, the valve must first be replaced during the inspection.
Note for changeover tests: we do not changeover test other cylinders as oxygen cylinders. We do not change-test other cylinders for oxygen, nor do we change-test fire extinguishing cylinders.
Ordering and request for quotation
You can order by emailing tilaukset@woikoski.fi, by calling 040 166 2023 or by visiting our Woikoski Store online. For more information about placing an order, please visit: Ordering products
You can request a quote by sending an email or calling. Industrial customer service: tel. 040 166 2023 or asiakaspalvelu@woikoski.fi
You can also contact the Area Sales Manager (delivery customers) or the Area Sales Representative (resale customers) in your area directly. You can find sales contact details here: Personnel
To place an order, we need the customer number or company name, gas type, bottle size, number of bottles, order reference, delivery address and information on returned bottles. For more information about placing an order, please visit: Ordering products
You can place an order by emailing tilaukset@woikoski.fi or by calling our customer service directly on 040 166 2023. You can see our range of welding consumables here: welding machines and torches, welding accessories and welding consumables.