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Frequently Asked Questions

Quotation

Is the VTO-NBNF available with different needle sizes?

The VTO-NBNF is available in 1.35 x 1.35 and 3 x 1.35 ID needles. (process x vent). Due to the design of the VTO-NBNF larger needle sizes are not recommended.

Where can I submit a request for quotation for sampling systems?

You can either submit your request for quotation online or you can contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative.

What is the lead time of my order?

The lead time strongly depends on the type of product(s). Indicative lead times are:

* Glass bottles, caps and septa: 1 to 2 weeks

* PP/PE bottles: 6 to 8 weeks

* Basic range of spare parts: 3 to 4 weeks

* Pre-configured sampling systems: an average of 6 weeks

* Other products: on request

What information is required for submitting a request for quotation?

You can find a list of the information we need to process your request for quotation, on the inquiry page.

How can I request a drawing of a sampling system?

To get a drawing of a specific sampling system, you can contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative.

What Non Destructive Examination (NDE) is available?

Dovianus is certified to conduct dye penetrant inspections and PMI testing. X-ray examination is subcontracted.

What are the standard tests you perform on a sampling system?

Each sampler undergoes functional tests and a hydrostatic pressure test at 1.5 times the design pressure.

Can I use a bottle with a different volume for my sampling system?

Yes, this is possible. For this you need to replace the sleeve of your sampler to match the dimensions of the bottle. Please note that some systems require additional modifications.

If you are still not sure whether you can use the bottle you have: feel free to contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative. Please make sure that you notify the contact person whether it concerns your own bottle or a Dopak bottle.

Can a needle assembly be replaced?

Yes, that's possible. You can find our range of needle assemblies on the spare parts page. Please also refer to our needle exchange program.

Can I order bottles, septa and caps separately?

Yes, that's possible. You can find our range of bottles, septa and caps on the consumables page.

Does Dovianus provide product demos and training?

Yes, we do. Please contact Dovianus in the Netherlands, Dopak Inc. in the USA or our local representative in your country, to discuss the possibilities. 

Do I need a bottle or a cylinder to take a sample?

In general our advice is to use a glass bottle for all samples with a vapor pressure up to a maximum of 0.7 bar. A cylinder can resist higher pressures than that.

In some cases the sampling product has a vapor pressure below 0.7 bar, but 'lighter components' can easily escape through the vent. In that case it is advisable to use a cylinder.

Please use the Dopak product selector to submit your requirements and find the most suitable Dopak sampling system to fit your needs.

You can either submit your request for quotation online or contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you need further advice on sampling in a bottle or a cylinder.

Do Dopak sampling systems have a CE mark?

All Dopak sampling systems will be supplied in compliance with Pressure Equipment Directive (PED) No. 2014/68/EU. This does not automatically mean that the samplers will be CE marked.

The PED divides pressure equipment in different categories based on pressure, volume and whether the product is a dangerous gas or liquid, or not.

Almost every Dopak sampling system falls under paragraph 4.3 of the PED. This paragraph describes the Sound Engineering Practice (SEP). The SEP indicates that the equipment shall be designed and manufactured in accordance with the sound engineering practice of a Member State in order to ensure safe use. Paragraph 4.3 of the Pressure Equipment Directive also indicates that such equipment shall not bear the CE marking.

In the exceptional case a Dopak sampling system falls under a category other than Sound Engineering Practice, the applicable requirements of that category will be followed, including the required Notified Body involvement. Such equipment will bear the CE marking.

Can I order spare parts for my sampling system?

Yes, that's possible. You can find our range of spare parts for sampling systems on the spare parts page.

Can I get my sampler fixed?

Yes, this is possible. Please refer to the repair procedure on the service procedures page.

What Dopak sampling systems are in stock?

Dovianus does not carry any stock for sampling systems. Each sampler is designed and built, matching the requirements of the client. Pre-configured sampling systems are built according to standard specifications and have a shorter lead time.

Please submit your request for quotation via the inquiry form. 

How long does it take to repair my sampler?

The repair time depends on the complexity of the repair and what parts need to be replaced. Please refer to the repair procedure for more information.

What brands of components are being used for Dopak sampling systems?

The brands of components that Dovianus normally uses for the Dopak samplers include: Hoke, Swagelok and Parker. However, we can use any brand of your preference.

Deliveries

What documentation do I get with the delivery?

In your delivery, you will find a USB flash drive with standard documentation such as:

* Operation manual

* ATEX certificates

* Data sheets

* Brochures

On request and at additional cost, we can also send you the following documentation in PDF format:

* GA drawing

* Test certificates

* Material certificates

* Et cetera

Do not hesitate to contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you would like more information on the documentation you receive.

The valve is leaking after the first use. What do I need to do?

Some Dopak sampling systems are equipped with a valve that has an end screw or a stem seal. If the valve leaks after first use, it is possible that the end screw or the stem seal needs to be tightened. Tightening or adjusting the end screw or stem seal will solve the leakage problem.

If you need more information on how to tighten the end screw or stem seal, please contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative.

Who will perform the installation and initial operation of the sampling system?

The Dopak sampling systems are ready to be installed. You will arrange for the installation and initial operation yourself.

Can I collect my order?

In the Netherlands you can collect your order by appointment. Please contact Dovianus in Bergschenhoek to make an appointment.

What are the transportation and delivery charges?

The transportation and delivery charges strongly depend on factors such as delivery address, size, weight and other conditions.

Please contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative for more information on the transportation and delivery charges.

What are the terms of delivery?

Dovianus' standard delivery terms are FCA. Other terms of delivery can be discussed.

Please refer to the Incoterms or contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you want more information on the terms of delivery.

Company information

What are your contact details?

The contact details for Dovianus in the Netherlands, Dopak Inc. in the USA or for one of our local representatives, can be found on the contact page.

What is the difference between Dovianus, Dopak Inc. and Dopak?

Dovianus is the name of our company in the Netherlands, Dopak Inc. is the name of our company in the USA and Dopak the brand name of our products.

Where can I find the bank details of Dovianus?

You can find our bank details on the contact page.

Where can I find the VAT number of Dovianus?

You can find our VAT number on the contact page.

Where can I find the Chamber of Commerce number of Dovianus?

You can find our Chamber of Commerce number on the contact page.

Where can I obtain a copy of the operation manual?

Please contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative to request a copy of any operation manual. Please clearly state your order number.

Where can I find a copy of your ISO 9000:2008 certification?

You can find a copy of our ISO 9000:2008 certification on this page.

Technical info

Is the VTO-NBNF an alternative for a secondary shut off?

Yes, the VTO-NBNF needle assembly is a suitable alternative.

Is the VTO-NBNF available with different needle sizes?

The VTO-NBNF is available in 1.35 x 1.35 and 3 x 1.35 ID needles. (process x vent). Due to the design of the VTO-NBNF larger needle sizes are not recommended.

Is it possible to replace a regular VTO needle assembly on an existing sampling system by a VTO-NBNF?

Yes, this is possible, however the guidance ring of the existing sleeve also needs to be replaced by a new model, suited for use in combination with the VTO-NBNF.

Also, since the VTO-NBNF is equipped with an O-ring the chemical compatibility needs to be checked.

Note that the clip of the existing sleeve will be lower, approx. 7,3 cm as a result of the replacement.

Do not hesitate to contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you would like more information on replacing a normal VTO needle assembly by a VTO-NBNF.

Is the VTO-NBNF an alternative for the primary sample valve?

No, the VTO-NBNF needle assembly is not a replacement for the primary sample valve. It is an extra safety feature on a Dopak sampling system.

Does the VTO-NBNF have any dead volume?

No, when the sample valve is in closed or purge position before the sample bottle is removed from the sleeve, the VTO-NBNF has no dead volume.

What is the value proposition of the VTO-NBNF needle assembly?

The VTO-NBNF prevents product flow when the sample bottle is not completely inserted into the sleeve.

 

As a side effect, sample bottles need to have a cap and septum to operate the VTO-NBNF.

 

This will drastically reduce the risk of spillage, which could cause hazard to the operator and environment.

 

How do I use a Dopak sampling system?

This depends on the sampling system you have or need. Please use the Dopak product selector to find the most suitable sampling system. When you have found the correct sampler, animations and data sheets are available for the product. Here you will be able to review product information and how to operate the specific sampler. 

What Dopak sampler is most suitable for us?

Please use the Dopak product selector to find the most suitable sampling system.

You can either submit your request for quotation online or contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you need further advice.

What documentation do I get with the delivery?

In your delivery, you will find a USB flash drive with standard documentation such as:

* Operation manual

* ATEX certificates

* Data sheets

* Brochures

On request and at additional cost, we can also send you the following documentation in PDF format:

* GA drawing

* Test certificates

* Material certificates

* Et cetera

Do not hesitate to contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you would like more information on the documentation you receive.

How can I request a drawing of a sampling system?

To get a drawing of a specific sampling system, you can contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative.

What Non Destructive Examination (NDE) is available?

Dovianus is certified to conduct dye penetrant inspections and PMI testing. X-ray examination is subcontracted.

What are the standard tests you perform on a sampling system?

Each sampler undergoes functional tests and a hydrostatic pressure tests at 1.5 times the design pressure.

What pressure is allowed on the sampler's vent?

The pressure on the vent (back pressure) may be up to 0.7 bar when sampling with a glass bottle.

Please use the Dopak product selector to find the most suitable sampling system to fit your requirements. 

Up to what vapor pressure can I use a glass or plastic bottle for sampling?

In general our advice is to use a glass or plastic bottle for all samples with a vapor pressure up to a maximum of 0.7 bar. A cylinder can resist higher pressures than that.

In some cases the product has a vapor pressure below 0.7 bar, but 'lighter components' can easily escape through the vent. In that case it is advisable to use a cylinder.

Please use the Dopak product selector to submit your requirements and find the most suitable Dopak sampling system to fit your needs.

Do not hesitate to contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you need further advice on sampling in a bottle.

Why does Dovianus advise a fixed volume sampler for an operating pressure above 8 bar?

The filling rate of a sample bottle depends amongst other things, on the operating pressure. At a higher pressure the filling rate is too high to guarantee safe sampling. There is the possibility to overfill the sample bottle. Therefore Dovianus sets the limit of 8 bar for the operating pressure.

With a fixed volume sampler, such as the Dopak sampling system type S23, the sample is taken independently of the operating pressure. The filling rate is therefore not influenced by the operating pressure. In addition, the volume of the sample chamber adapts to the volume of the sample bottle, reducing the chance of overfilling the sample bottle to an absolute minimum.

Please use the Dopak product selector to submit your requirements and find the most suitable Dopak sampling system to fit your needs.

Why is a fixed volume sampler suitable for sampling liquids under high pressure?

The filling rate of a sample bottle depends amongst other things, on the operating pressure. At a higher pressure the filling rate is too high to guarantee safe sampling. There is the possibility to overfill the sample bottle. Therefore Dovianus sets the limit of 8 bar for the operating pressure.

With a fixed volume sampler, such as the Dopak sampling system type S23, the sample is taken independently of the operating pressure. The filling rate is therefore not influenced by the operating pressure. In addition, the volume of the sample chamber adapts to the volume of the sample bottle, reducing the chance of overfilling the sample bottle to an absolute minimum.

Please use the Dopak product selector to submit your requirements and find the most suitable Dopak sampling system to fit your needs.

What is the difference between an outage tube, expansion chamber and additional safety cylinder?

An outage tube, expansion chamber and additional safety cylinder are different methods of reaching the same result: to prevent the sample cylinder to be filled 100% with the liquid or liquefied gas.

 

Liquids and liquefied gases are not compressible. If a completely filled sample cylinder warms up (either by the sun or when it is being transferred from a cold, outside temperature to a warm, indoor temperature), the liquid or liquefied gas will expand. This causes the pressure in the cylinder to increase rapidly, possibly to unacceptable levels.

Outage tube

An outage tube is a tube that is mounted into the cylinder. It creates a safe and compressible 'gas bubble' in the cylinder to regulate the pressure (internal outage).

Expansion chamber

When using an expansion chamber, the sample cylinder is initially filled 100%. Subsequently a connection is made between the cylinder and the expansion chamber. This way, part of the liquid or liquefied gas will run into the expansion chamber, creating a safe and compressible 'gas bubble' in the cylinder.

Additional safety cylinder

With the third method, the sample cylinder is connected to a pressure relief valve and an (small) extra cylinder (the so-called 'piggyback'). In this case the cylinder remains completely filled. When the pressure in the cylinder increases to an unacceptable level, the overpressure valve will open and a connection is being established to the extra cylinder. This extra cylinder is filled with (compressible) air, keeping the pressure to acceptable levels.

What material are Dopak sampling systems made of?

The standard material used for Dopak sampling systems is SS316 stainless steel. The wetted parts however, can be manufactured in a diversity of exotic material such as Hastelloy, (Super) Duplex, Monel, Inconel, Titanium or 6Mo.

Do not hesitate to contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you have further questions on the material used for our sampling systems.

Does Dovianus offer other systems than the regular Dopak series?

Yes, it is possible to build a sampling system according to your P&ID/layout.

Do not hesitate to contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you would like more information on custom-made sampling systems.

Do Dopak sampling systems have a CE mark?

All Dopak sampling systems will be supplied in compliance with Pressure Equipment Directive (PED) No. 2014/68/EU. This does not automatically mean that the samplers will be CE marked.

The PED divides pressure equipment in different categories based on pressure, volume and whether the product is a dangerous gas or liquid, or not.

Almost every Dopak sampling system falls under paragraph 4.3 of the PED. This paragraph describes the Sound Engineering Practice (SEP). The SEP indicates that the equipment shall be designed and manufactured in accordance with the sound engineering practice of a Member State in order to ensure safe use. Paragraph 4.3 of the Pressure Equipment Directive also indicates that such equipment shall not bear the CE marking.

In the exceptional case a Dopak sampling system falls under a category other than Sound Engineering Practice, the applicable requirements of that category will be followed, including the required Notified Body involvement. Such equipment will bear the CE marking.

Can I order spare parts for my sampling system?

Yes, that's possible. You can find our spare parts for sampling systems on the spare parts page.

What brands are being used for Dopak's sampling systems components?

The brands that Dovianus normally uses for the Dopak samplers include: Hoke, Swagelok and Parker. However, we can use any brand of your preference.

How can I safely empty my bottle or cylinder?

You can safely empty a bottle with the 'Sample Recovery System'. You can safely empty a cylinder with the 'Cylinder Emptying System'.

You can submit your request for quotation on the inquiry page

Troubleshooting

Is it possible to replace a regular VTO needle assembly on an existing sampling system by a VTO-NBNF?

Yes, this is possible, however the guidance ring of the existing sleeve also needs to be replaced by a new model, suited for use in combination with the VTO-NBNF.

Also, since the VTO-NBNF is equipped with an O-ring the chemical compatibility needs to be checked.

Note that the clip of the existing sleeve will be lower, approx. 7,3 cm as a result of the replacement.

Do not hesitate to contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you would like more information on replacing a normal VTO needle assembly by a VTO-NBNF.

Is the VTO-NBNF an alternative for a secondary shut off?

Yes, the VTO-NBNF needle assembly is a suitable alternative.

What do I need to do when the septum doesn't seal properly?

There could be a number of reasons why a septum doesn't seal properly:

1. The septum has been used before. We strongly advise you to use a new septum for each sampling. Check the septum carefully and change the septum if necessary.

2. An incompatible combination of process needle and septum material is used.
Some needle diameters are too big for certain septum materials. Determine what septum material you want to use and what the diameter is of the process needle of your sampling system. Check whether this is the right combination.

3. The needle assembly is damaged or the needles are not sharp enough. Needle assembly needs to be replaced.

4. The vapor pressure of your product is too high, causing the septum to act as a pressure release (safety) device. Sample container may be changed to a cylinder type.

Please contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you would like more information on the compatibility of septum material and process needle.

The valve is leaking after the first use. What do I need to do?

Some Dopak sampling systems are equipped with a valve that has an end screw or a stem seal. If the valve leaks after first use, it is possible that the end screw or the stem seal needs to be tightened. Tightening or adjusting the end screw or stem seal will solve the leakage problem.

If you need more information on how to tighten the end screw or stem seal, please contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative.

Do I need a bottle or a cylinder to take a sample?

In general our advice is to use a glass bottle for all samples with a vapor pressure up to a maximum of 0.7 bar. A cylinder can resist higher pressures than that.

In some cases the sampling product has a vapor pressure below 0.7 bar, but 'lighter components' can easily escape through the vent. In that case it is advisable to use a cylinder.

Please use the Dopak product selector to submit your requirements and find the most suitable Dopak sampling system to fit your needs.

You can either submit your request for quotation online or contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you need further advice on sampling in a bottle or a cylinder.

Can I use a bottle with a different volume for my sampling system?

Yes, this is possible. For this you need to adjust the sleeve of your sampler to match the dimensions of the bottle. Please note that some systems require additional modifications.

If you are still not sure whether you can use the bottle you have: feel free to contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative. Please make sure that you notify the contact person whether it concerns your own bottle or a Dopak bottle.

Can I replace a needle assembly myself?

Yes, that's possible. You can find our range of needle assemblies on the spare parts page. Please also refer to our needle exchange program.

What do I need to do when the needles for my sampling system are damaged?

You can change damaged needles via our needle exchange program. 

How often can I use the septum?

A septum is only used once. You need to change the septum for each new sampling. This is the only way to guarantee an emission free sample and the safety of your operator and the environment. 

Can I get my sampler fixed?

Yes, this is possible. Please refer to the repair procedure on the service procedures page.

Filling the sample bottle is going too slow. What could be the cause?

Most likely the viscosity of the product is too high for the needle assembly. It could also be possible that the needle assembly is blocked or that the operating pressure is too low. Use a different needle assembly to increase the filling rate. Order a different needle assembly via our needle exchange program.

Contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you need advice on what needle assembly or bottle to use. You can also contact us when the needle assembly is blocked or when the operating pressure is too low.

Filling the sample bottle is going too fast. What could be the cause?

Either the bottle is too small, the process needle of the needle assembly is too big or the operating pressure is above 8 bar. Use a different bottle or needle assembly to decrease the filling rate. Order a different needle assembly via our needle exchange program.

Contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you need advice on what needle assembly or bottle to use. You can also contact us in case the operating pressure is above 8 bar. 

Customer support

Does the VTO-NBNF have any dead volume?

No, when the sample valve is in closed or purge position before the sample bottle is removed from the sleeve, the VTO-NBNF has no dead volume.

Is the VTO-NBNF an alternative for the primary sample valve?

No, the VTO-NBNF needle assembly is not a replacement for the primary sample valve. It is an extra safety feature on a Dopak sampling system.

Is it possible to replace a regular VTO needle assembly on an existing sampling system by a VTO-NBNF?

Yes, this is possible, however the guidance ring of the existing sleeve also needs to be replaced by a new model, suited for use in combination with the VTO-NBNF.

Also, since the VTO-NBNF is equipped with an O-ring the chemical compatibility needs to be checked.

Note that the clip of the existing sleeve will be lower, approx. 7,3 cm as a result of the replacement.

Do not hesitate to contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative in case you would like more information on replacing a normal VTO needle assembly by a VTO-NBNF.

How can I request a drawing of a sampling system?

To get a drawing of a specific sampling system, you can contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative.

Can I replace a needle assembly myself?

Yes, that's possible. You can find our range of needle assemblies on the spare parts page. Please also refer to our needle exchange program.

Where can I obtain a copy of the operation manual?

Please contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative to request a copy of any operation manual. Please clearly state your order number.

The valve is leaking after the first use. What do I need to do?

Some Dopak sampling systems are equipped with a valve that has an end screw or a stem seal. If the valve leaks after first use, it is possible that the end screw or the stem seal needs to be tightened. Tightening or adjusting the end screw or stem seal will solve the leakage problem.

If you need more information on how to tighten the end screw or stem seal, please contact Dovianus in the Netherlands, Dopak Inc. in the USA or your local representative.

Does Dovianus provide product demos and training?

Yes, we do. Please contact Dovianus in the Netherlands, Dopak Inc. in the USA or our local representative in your country, to discuss the possibilities. 

Who will perform the installation and initial operation of the sampling system?

The Dopak sampling systems are ready to be installed. You will arrange for the installation and initial operation yourself.

Can I order spare parts for my sampling system?

Yes, that's possible. You can find our range of spare parts for sampling systems on the spare parts page.

Can I get my sampler fixed?

Yes, this is possible. Please refer to the repair procedure on the service procedures page.