derwent james safety equipment & consultancy

Providing outstanding safety equipment, consultancy and expertise for your company.
Because safety is a necessity, not a commodity

Tel: 01332 673700 Mobile: 07968 512311 Email:

process industry safety

Dopak bottle septa

Dopak septa and septum

Dopak sampling systems use a variety of septa materials and sizes. Make sure you have the correct Dopak bottle septa when sampling your hazardous chemicals. Dopak have stock of all septa ready for shipment. So, as the UK reps for Dopak you can contact us here for technical and commercial support if you have any questions.

Below is a technical description of each septa material along with the individual septum part numbers and septa set part numbers. When ordering septa please order them in sets and use the set part number mentioned below.

Order your Dopak septa directly from the Dopak warehouse


Natural rubber septa

Excellent mechanical and elastic properties and is highly tear resistant. Due to the influence of sunlight and ozone aging resistance is moderate. For non-corrosive materials, and acidic and alcoholic solutions this material is suitable. Although its chemical resistance in general is moderate, short exposure time (e.g. less than 24 hours, as is not unusual in sampling situations) allows for application with many more aggressive chemicals.

MaterialBottle sizeSepta PNSet PNSet quantity
Natural rubberPP2011266002003299100
Natural rubberPP22TBATBA100
Natural rubberPP2411255002006300100
Natural rubberPP2511200001940000127
Natural rubberPP2811201001940100100
Natural rubberGL3211242001944200100
Natural rubberPP3311248001944800100
Natural rubberPP3611202001940200100
Natural rubberGL4511203001940300100

EPDM septa

Good mechanical and elastic properties, excellent aging and good chemical resistance capabilities. A low cost combined with the above features makes this septum a very good choice.

MaterialSizeSeptum PNSet PNSet quantity

Silicone rubber septa

Good mechanical and elastic properties. Its prime advantages are excellent heat resistance and non-oxidizing properties. The complicated fabrication however makes it relatively expensive. Almost no aging occurs, and it is inert to most solvents with the possible exception of the aliphatic type.

MaterialBottle sizeSepta PNSet PNSet quantity

Teflon coated butyl rubber septa

The combination of these two materials provide the best choice when considering elasticity properties and chemical and tear resistance. The elasticity and high tear resistance of the butyl is combined with the almost total chemical inertness of the PTFE (thickness 0.2 mm). The PTFE faces the sample liquid, providing optimal chemical compatibility; the butyl rubber backing provides the seal, only a very large tear would allow contact between the butyl rubber and the sample medium, therefore this septum can only be used with smaller needle sizes.

MaterialBottle sizeSepta PNSet PNSet quantity
Teflon coated butylpp201126900TBA100
Teflon coated butylpp2220192722019274100
Teflon coated butylpp2411247001944700100
Teflon coated butylpp2511216001941600127
Teflon coated butylpp2811217001941700100
Teflon coated butylGL3211241001944100100
Teflon coated butylpp3311251001945100100
Teflon coated butylpp3611218001941800100
Teflon coated butylGL4511219001941900100

Teflon coated silicone septa

Incorporates the advantages of silicone and PTFE. The heat-resistance of both materials and the total chemical inertness of the PTFE (thickness 0.2 mm) make this septum the best choice when sampling at elevated temperatures. The PTFE faces the sample liquid in the same manner as the PTFE coated butyl septum, therefore attention to the needle sizes should be considered when using this material.

MaterialBottle sizeSepta PNSet PNSet quantity
Teflon coated Siliconepp201127100TBA100
Teflon coated Siliconepp22TBATBA100
Teflon coated Siliconepp241126000TBA100
Teflon coated Siliconepp2511220001942000127
Teflon coated Siliconepp2811221001942100100
Teflon coated SiliconeGL3211239001943900100
Teflon coated Siliconepp331125300TBA100
Teflon coated Siliconepp3611222001942200100
Teflon coated SiliconeGL4511223001942300100

Viton septa

(FKM, fluor elastomer or fluorcarbon rubber) has only moderate mechanical and elastic
properties. Prime advantages are the high maximum temperature is 210 °C (410 °F) and
good chemical resistance towards most materials and solutions.

MaterialBottle sizeSepta PNSet PNSet quantity

Dopak support in the UK is available in many ways…telephone, email, direct message, social media. Contact us in whichever way works for you but we are your first point of call for all things Dopak. When youre ready to place your order send this to

product image
Author Rating
Aggregate Rating
5 based on 1 votes
Brand Name
Product Name
Dopak bottle septa
Product Availability
Available in Stock

Share this

Back to Latest News

Providing outstanding safety equipment, consultancy and expertise for your company.
Because safety is a necessity, not a commodity

Derwent James Ltd © 2009-2020 | HTML Sitemap | Privacy Policy

Website design by Web Design Derby | Cloud Computing