Étanchéité · Joints clamp Normes et surfaces

Engraved clamp seals: traceability that survives the bag

Two years of investigation for particles in a tank. Everyone knew what type of joint to look for. No one knew which one was up, nor from what lot he came from.

Par Jean-Philippe Pavard, ingénieur, Tubes TechnologiesPublié le 15/10/2026Lecture 11 min

the essential

Annex 1 of the GMP does not require engraving the joints: it requires proving control of each component in contact produced.
The label of the bag does not follow the joint once mounted: this is the weak link in traceability.
On request to order, the laser engraved clamp seal bears its batch number on the outer flange, excluding wet, legible tight collar and after SIP.
The FDA / USP Class VI certificate of the lot bears the same number: the proof travels with the part.
Engraving available in silicone, EPDM, FKM (Viton), PTFE and PTFE wrapped, depending on the manufacturer selected.

Annex 1 of GMPs does not require engraving a batch number on a clamp joint anywhere. It requires something else, more difficult: to be able to demonstrate, piece by piece, the mastery of everything related to the product. The engraved clamp joint is the easiest way to hold this requirement once the seal has left its bag.

The weak link: the label of the bag

Today, the traceability of a clamp joint is based on the label of its bag. As soon as the seal is taken out of the packaging and mounted on the installation, this documentary link is broken. The material certificate still exists. He no longer follows the room.

A sterile production site receives four to five inspections per year: ANSM, FDA, customers, internal audits. LANSM can happen without warning. The essential is played on the documents, and one day, the inspector’s finger falls on the maintenance of an EPPI loop.

A few dozen clamp joints, from 12.7 to 63.5 mm. PTFE, EPDM coated PTFE. SIPs at 121.1°C for 20 minutes, every week or every quarter depending on the loop. Simple question: this joint, which lot, which certificate, asked when?

The good news: the certificate exists. The worst: he sleeps in a binder, and the joint left his bag eight months ago.

what Annex 1 of the GMP really requires

The revised Annex 1 (“Manufacture of Sterile Medicines”) was published by the European Commission on August 25, 2022. It has been applied since August 25, 2023, and since August 25, 2024 for its item 8.123 on freeze dryers. In France, it constitutes the guideline LD.1 of the LANSM GMP Guide. The sterile production sites have been revising since their supplier requirements, in particular for elastomers in product contact.

The text is not about engraving. He talks about evidence. Five points directly affect the clamp joint:

Point de l'Annexe 1	Ce que dit le texte	Conséquence pour le joint clamp
2.3	Une stratégie de contrôle de la contamination (CCS) définit tous les points critiques de contrôle et l'efficacité des moyens de maîtrise.	Le joint en contact produit est un point critique : sa matière, sa conformité et sa durée de vie doivent être justifiées.
2.5	La CCS couvre notamment les équipements, l'agrément des fournisseurs de composants clés et la maintenance préventive.	Une fréquence de remplacement doit être définie et prouvée. Sans identification, impossible de savoir depuis quand un joint est en place.
3.2	Toute non-conformité fait l'objet d'une investigation ; l'inclusion ou l'exclusion de chaque lot doit être justifiée et enregistrée.	Un fragment de joint ou une fuite après SIP doit pouvoir être rattaché à son lot et à son certificat matière.
5.7	Une maintenance non planifiée sur un équipement critique pour la stérilité impose une évaluation d'impact enregistrée.	Le joint remplacé en urgence doit être identifié, comme celui qu'il remplace.
8.129	L'intégrité des composants des connexions aseptiques est assurée et documentée dans la CCS ; l'évaluation des fournisseurs inclut les modes de défaillance.	Le fournisseur de joints doit pouvoir documenter matière, lot et tenue en service.

Paraphrase du texte, d'après l'Annexe 1 des BPF (LD.1 du guide des BPF, ANSM).

what to remember

Annex 1 does not impose engraving as such. It requires demonstrating mastery of each element that can contaminate the product, and the joint in contact produced is one of them. The engraved joint clamp removes the weak link: dependence on a sachet or label that does not follow the part.

The cost of a joint that cannot be identified

At the first deviation, particles or a leak after SIP, the batch is blocked. Point 3.2 then becomes very concrete: it is necessary to justify in writing each lot included in the investigation or excluded from its scope.

Without a legible lot on the part, everything that has turned with “this type of joint” becomes suspicious. On a site that produces 5 to 6 lots per week, at €500,000 per lot, each week of production that cannot be excluded represents 2.5 to 3 million euros under investigation. Faced with this figure, the unit additional cost of an engraved clamp joint is negligible.

The CCS is the client who writes it. It is he who defends her before the inspector. as much as he has the proofs in hand.

The case of sterile ophthalmic products

An ophthalmic gel combines the factors that make individual joint traceability essential:

Mandatory sterility. The product is applied to the eye: any microbial or particulate contamination is a critical defect.
often aseptic production. A viscous gel is poorly filtered and often poorly supports terminal sterilization. Sterility is therefore based on sterilized equipment and their components, including seals.
repeated thermal cycles. Preparation tanks and transfer lines undergo frequent CIPs and SIPs, which age elastomers.
visible particles. A delastomer fragment in a transparent gel is detected at visual inspection and triggers an investigation.

For this type of site, an unidentifiable joint after assembly is a potential deviation during an inspection. The engraved clamp seal closes this door.

The engraved joint clamp: what is marked, where and how

At Tubes Technologies, the engraved clamp joint is an option: laser engraving of the batch number is asked when ordering, on the clamp FDA / USP Class VI clamp joints. It is not systematic. The marking does not make any material: neither ink nor label. It is placed on the outer collar, out of the fluid vein and out of the wet area, and remains legible once the collar is tight. It is due to SIP cycles. The certificate of conformity of the lot bears the same number: the proof travels with the part.

The proposed marked data: the manufacturer’s batch number, the material code (SIL, EPDM, PTFE, etc.) and the nominal size. A specific marking, for example the equipment marker, can be added at the customer’s request. The engraved material code replaces the color dot that some manufacturers use to identify the elastomer: a pellet reads badly, a text reads.

Sizes, engravable materials and marking contents vary from manufacturer to manufacturer. Depending on the ranges, the engraving covers the clamp joints from 1/2″ to 4″, i.e. tubes from 12.7 to 101.6 mm in outer diameter: the entire range of a current EPP loop. It applies to silicone, LEPDM, FKM, PTFE, Buna (NBR), PTFE / stainless steel composites such as seals tuf-steel and tuff-flex, and sometimes to orifice plates and sieves. Manufacturers announce a legible marking throughout the service life of the seal; Some also certify their ADI Free joints (without animal ingredient).

We work with several engraved clamp joint manufacturers: Dockweiler, Newman Sanitary Gasket, Rubber Fab and Techné. Our role: source the engraved joint clamp adapted to each site, according to its preferences (manufacturer already qualified, material, execution) and its regulatory requirements (FDA, USP Class VI, ADI Free, Annex 1 of GMPs). Several qualified sources also secure the supply.

Matière gravée	Exécution	Fiche produit
Silicone (platine)	Type I sans lèvre ou type II à lèvre de centrage, selon matière	Joint clamp silicone
EPDM	Type I ou type II selon matière	Joint clamp EPDM
FKM (Viton)	Type I ou type II selon matière	Joint clamp FKM
PTFE	Type I ou type II selon matière	Joint clamp PTFE
PTFE enveloppé (jaquette)	Selon matière	Joint clamp revêtu PTFE

the chain of traceability, from reception to replacement

An engraved clamp joint is only used if it is connected to the site’s quality system. The chain is in five links:

The engraved number Refers to the material and batch conformity certificate (FDA, USP Class VI).
at the reception, the site registers the lot in its quality system.
In assembly, the number is reported in the equipment register and the batch file.
in use, the SIP and autoclave cycles are counted by joint until replacement, which justifies preventive replacement.
In case of deviation, the batch of the joint in question is identified immediately, and the investigation perimeter is reduced by as much.

Mark without creating a new risk

Marking an engraved clamp seal should not create any new risk of contamination. Four points are to be justified, and each directly feeds the customer’s supplier qualification and CCS:

Point de contrôle	Exigence	Preuve à fournir
État de surface	Aucune altération de la face d'étanchéité ni de la face en contact produit	Plan de marquage, photo, contrôle visuel
Particules	Aucun résidu ni débris lié au marquage	Procédé sans encre ni étiquette, nettoyage après marquage
Extractibles / relargables	Profil inchangé par rapport au joint non marqué	Déclaration fabricant ou données d'essai
Conformité matière	FDA et USP Class VI maintenues	Certificat du lot reprenant le numéro gravé

Switch to engraved clamp joints: the 4-step method

Inventory The sizes, materials and annual quantities concerned, loop by loop.
Validate the content of the marking : lot alone, or lot + material + size, and specify the engraving option with each order.
Test A series of samples engraved with the associated type certificate, to validate the rendering before order.
Integrate the reference From the engraved joint clamp to the site supplier specifications and the CCS.

For elastomers and standard sealing, see also our article on theASME BPE (Part PM and Part MC).

Documents to download

PDFGuide de sélection des joints clampExemple de catalogue fabricant : gammes, matières, conformités FDA et USP Class VIEN PDFListe de résistance chimique des élastomèresCompatibilité par fluide et par matièreEN PDFFiche technique : dimensions des jointsCotes des joints clamp par tailleFR

frequently asked questions

L'Annexe 1 des BPF impose-t-elle de graver les joints clamp ?

Non. Elle impose de démontrer la maîtrise de chaque élément pouvant contaminer le produit (stratégie de contrôle de la contamination, maintenance, investigation des déviations). Le joint clamp gravé est un moyen simple d'apporter cette preuve après le montage.

Le marquage peut-il abîmer le joint ou contaminer le produit ?

Sur un joint clamp gravé, le marquage laser est placé sur la collerette extérieure, hors de la zone mouillée, sans apport de matière. Les conformités FDA et USP Class VI sont reprises sur le certificat du lot gravé.

L'étiquette du sachet ne suffit-elle pas ?

Non. L'étiquette ne suit pas la pièce une fois montée. C'est précisément ce qu'un inspecteur peut relever lors d'un audit de maintenance. Le joint clamp gravé, lui, porte son lot sur la pièce.

Tous les joints clamp sont-ils livrés gravés ?

Non. Le joint clamp gravé est une option proposée sur demande, à préciser à la commande. Sans demande, le joint est livré standard, tracé par l'étiquette de son sachet.

Quelles matières de joints clamp peuvent être gravées ?

Le silicone, l'EPDM, le FKM (Viton), le PTFE et le PTFE enveloppé (jaquette), soit les matières les plus utilisées en production stérile. Selon les fabricants s'ajoutent le Buna (NBR), des composites PTFE / inox, les plaques à orifice et les tamis, de 1/2" à 4".

Le marquage résiste-t-il aux cycles SIP ?

Oui. Sur un joint clamp gravé, le marquage laser reste lisible après les cycles de stérilisation en place ; les fabricants l'annoncent lisible pendant toute la durée de service du joint. On peut donc compter les cycles par joint jusqu'à son remplacement.

Qu'est-ce qui est gravé sur le joint ?

Sur un joint clamp gravé : le numéro de lot fabricant, et sur demande le code matière (SIL, EPDM, PTFE…) et la taille nominale.

Un joint clamp gravé coûte-t-il plus cher ?

Le surcoût unitaire est faible face au coût d'une investigation ou d'un lot bloqué. Il remplace aussi le temps passé à retrouver un certificat.

Jean-Philippe Pavard

Auteur · Ingénieur, Tubes Technologies · tuyauterie procédé, agitation magnétique, disques de rupture, étanchéité

Ancien ingénieur mise en route et expert traitement d'eau dans un grand groupe alimentaire, puis chargé d'affaires en pharmaceutique, microélectronique et agroalimentaire. Profil LinkedIn

Pierre Goubert

Co-éditeur · Spécialiste des composants aseptiques à rugosité contrôlée, Tubes Technologies

Profil LinkedIn

The clamp seals mentioned in this article

FDA / USP Class VI clamp seals, available in engraved clamp seal (laser batch number) on request to order, distributed by Tubes Technologies.

Silicone platine · FDA / USP Class VIJoint clamp siliconeType I ou type II, gravure sur demandeVoir la fiche →EPDM · FDA / USP Class VIJoint clamp EPDMType I ou type II, gravure sur demandeVoir la fiche →PTFE · FDA / USP Class VIJoint clamp PTFEType I ou type II, gravure sur demandeVoir la fiche →FKM (Viton) · FDA / USP Class VIJoint clamp FKMType I ou type II, gravure sur demandeVoir la fiche →PTFE enveloppé · FDA / USP Class VIJoint clamp revêtu PTFEJaquette PTFE sur EPDM, gravure sur demandeVoir la fiche →

Have your clamp joints engraved

To switch to the engraved clamp joint, identify with our team the sizes, materials and quantities of your loops, validate the content of the marking, then receive samples engraved with their standard certificate before the first order.