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Last reviewed: September 2, 2026.
The phrase ‘all wetted parts in 316L’ is not a complete veterinary filling-machine material specification. Product can also contact gaskets, O-rings, hoses, valve seats, tubing, pump elements, nozzle seals, sensors, filters and temporary transfer connections. Cleaning and sanitizing fluids may be more aggressive than the formulation, and elevated temperature or long exposure can change the result.
The equipment URS should therefore turn product and cleaning knowledge into a contact-material matrix. For every location, it should identify the medium, concentration, temperature, pressure, contact time, cleaning state, mechanical duty, proposed material, surface requirement, supplier evidence, owner review and change-control rule. Unknown data should remain visible as open items rather than being replaced by a generic material claim.
This article is deliberately limited to equipment-contact materials. It is not a general veterinary drug compatibility paper and does not replace toxicological, extractables and leachables, process-validation or regulatory assessment by the product owner. The goal is a defensible URS and FAT evidence package for fillers handling liquids, suspensions, creams, ointments, gels and pastes.
Quick answer: Specify veterinary filler wetted parts by mapping every product and cleaning-contact location to formulation composition, concentration, temperature, pressure, contact time, mechanical duty and cleaning exposure. Screen stainless steel, elastomer, hose, valve-seat and pump materials with supplier data, then confirm the final combination through documented risk assessment and representative testing. The product owner approves suitability; the equipment supplier provides traceable materials, construction records and agreed FAT evidence.
Define the Responsibility Boundary Before Choosing Materials
Direct answer: The manufacturer owns product-quality and regulatory suitability; the machine supplier owns conformity to the approved equipment specification and the evidence included in its scope.
Assign roles for formulation disclosure, chemical compatibility screening, toxicological or extractables-and-leachables assessment, hygienic design, material certificates, fabrication, cleaning development, validation and change control. A supplier can recommend a material based on disclosed conditions, but it cannot approve a proprietary formulation it has not seen or make the product owner’s regulatory conclusion.
21 CFR 211.65 requires, in the applicable U.S. drug context, that product-contact equipment surfaces not be reactive, additive or absorptive in a way that alters drug safety, identity, strength, quality or purity beyond established requirements. This is a performance requirement, not a statement that one stainless steel or gasket grade is universally acceptable.
Create a responsibility matrix at URS stage. Mark which claims require a certificate, drawing, supplier compatibility statement, user risk assessment, laboratory study, cleaning trial or qualification protocol. Do not use ‘GMP compliant’ as a substitute for the actual deliverable and acceptance owner.
Build a Formulation and Process Data Package
Direct answer: Material selection is only as reliable as the composition and operating conditions disclosed for each contact state.
List active and inactive ingredients, solvents, oils, surfactants, preservatives, salts, acids, bases, flavors, colorants, suspended solids and any known swelling, staining or stress-cracking concerns. If composition is confidential, use a controlled disclosure or provide a compatibility decision signed by the owner’s qualified material expert; do not omit the risk silently.
Record concentration ranges, pH, density, viscosity with method and temperature, particle condition, operating and maximum temperatures, pressure or vacuum, oxygen or light sensitivity, and maximum continuous and cumulative contact time. Include startup, hold, recirculation, stoppage, low-level and batch-end states because exposure can differ from normal filling.
Map product paths from preparation and transfer through the meter, valves, hoses and nozzles. The KING PACK emulsifier and mixer platform is relevant where veterinary creams, ointments or gels move from vacuum emulsification into filling; the transfer interface must use the same approved material boundary.
| Required input | Minimum detail | Why it changes the decision | Owner evidence |
|---|---|---|---|
| Formulation | Components and concentration ranges | Chemical attack, absorption, swelling or adsorption risk | Controlled formula or expert assessment |
| Process state | Temperature, pressure, vacuum and agitation | Stress and exposure differ from storage conditions | Approved process range |
| Contact time | Continuous, cumulative and hold duration | Compatibility ratings may depend on duration | Batch and stoppage model |
| Mechanical duty | Static, dynamic, flexing, sliding or pumped | Wear and compression behavior affect seals and hoses | Equipment duty map |
| Cleaning exposure | Agent, concentration, temperature, time and rinse | Cleaning can be the worst chemical or thermal case | Cleaning strategy and supplier data |
Specify Stainless-Steel Product Surfaces Beyond the Grade Name
Direct answer: If 316L is selected, the URS should also define location, construction, finish, weld treatment, traceability and acceptance evidence; 316L alone does not prove suitability.
Identify every stainless-steel product-contact component and whether it is fabricated, machined, cast or supplied as a standard part. Specify the required alloy designation and accepted equivalent system, then define material identification and traceability. The user should review compatibility with the formulation and cleaning conditions, especially chlorides, strong chemicals, high temperature or long exposure.
State the required internal surface condition using an agreed measurement and sampling plan. A numerical roughness limit should only be inserted when justified by the process and quality strategy. Define how welds are finished, inspected and documented, and whether passivation, electropolishing or another treatment is required. Avoid promising a finish that cannot be measured at inaccessible locations.
Request material certificates or certificates of conformity at the agreed level, a product-contact parts list, weld map where applicable, surface-finish evidence, treatment records and controlled drawings. Link each record to an equipment tag or drawing position so the package can be audited after delivery.
Map Every Nonmetallic Product-Contact Part
Direct answer: Gaskets, O-rings, tubing, hoses, valve seats, diaphragms and pump elements require their own material and duty review because their failure modes differ from stainless steel.
Walk the complete product path and list each removable and fixed nonmetallic part. Include seemingly minor items such as nozzle O-rings, sensor seals, piston cups, hose liners, tri-clamp gaskets, sampling-port seals and filter media. Record manufacturer, compound or grade, color where controlled, hardness if relevant, location and replacement part number.
Distinguish static seals from dynamic seals. A material that screens well against a liquid may still be unsuitable for repeated flexing, sliding, compression set, abrasion or pressure cycling. Hose bend radius, vacuum resistance, pressure rating and repeated cleaning also influence service life. Use the component manufacturer’s data for the actual compound, not only the polymer family name.
For a dosing-syringe or piston-based veterinary paste system, the KING PACK syringe filling machine range provides equipment context. The plunger, barrel, piston seal, hose, valve and nozzle contacts still need project-specific review.
Screen Elastomers and Seals by Compound and Duty
Direct answer: Polymer family names are only a first screen; final selection must use the actual compound, media, temperature, contact time, pressure and motion.
Common project discussions may include EPDM, FKM, NBR, silicone, PTFE-based materials or FFKM, but none is automatically best for all veterinary products and cleaning agents. Compounds within one family can differ in cure system, fillers, hardness, extractables profile and service limits. Ask the seal supplier for data tied to the proposed compound and application.
Parker’s O-Ring Handbook describes chemical properties, physical conditions, aging, abrasion and gland design as interacting selection criteria and states that compatibility tables are guidelines. DuPont’s chemical-resistance tools likewise use chemicals and operating conditions to support product selection. These are screening resources, not approval for a finished medicinal product process.
When data are uncertain, run controlled immersion or functional tests with the actual compound under representative and worst-case exposure. Evaluate dimensional change, mass change, hardness, tensile or compression behavior where relevant, visible damage, leakage and functional cycling. The owner should define acceptance and any toxicological follow-up.
| Candidate family | Useful screening questions | Mechanical questions | URS evidence |
|---|---|---|---|
| EPDM | Exposure to product, hot water, steam and cleaning chemistry? | Static or dynamic; compression set; pressure | Actual compound data and test conclusion |
| FKM | Solvent, oil, acid/base and temperature combination? | Flexing, wear, low-temperature behavior | Grade-specific supplier statement |
| NBR/HNBR | Oil, water, solvent and cleaning compatibility? | Abrasion, temperature and compression duty | Compound identification and limits |
| Silicone | Product absorption, cleaning and temperature? | Tear, wear and repeated flexing | Grade, cure and application evidence |
| PTFE/FFKM | Is the broader resistance needed and justified? | Cold flow, sealing force, wear or groove design | Application-specific design and supplier data |
Treat Cleaning as a Separate Compatibility Case
Direct answer: For each cleaning step, specify chemical name, concentration, temperature, contact time, flow or mechanical action and rinse condition; the cleaning cycle may be more severe than production.
Build a cleaning-media table that includes alkaline or acidic detergents, oxidizers, disinfectants, alcohols, hot water, steam where used and purified-water rinses. Record normal and maximum concentration, preparation method, temperature, recirculation or soak time, frequency and the state of each valve, seal and hose during cleaning.
Compatibility can change when temperature or concentration rises, when several agents are used sequentially, or when a seal remains compressed during exposure. Residual product can also react with cleaning chemistry. Review both product-only and cleaning-only cases plus credible mixtures during transition or incomplete rinse.
21 CFR 211.67 requires written cleaning and maintenance procedures and records in the applicable U.S. drug context. The regulation does not select the material for the user; it reinforces the need to define methods, materials, disassembly, protection and inspection. Cleaning validation remains site-specific.
Separate Chemical Compatibility from Extractables and Leachables
Direct answer: A seal can remain dimensionally functional yet still require an extractables-and-leachables or adsorption assessment; visual compatibility is not the complete quality decision.
Chemical-resistance charts usually focus on swelling, hardness, strength or service life. They do not by themselves establish that substances migrating from equipment-contact materials are acceptable for a veterinary product. They also may not address adsorption of active or preservative onto a polymer surface.
The product owner should use formulation, route of administration, dose, contact area, contact time, temperature, process stage and downstream controls to decide what toxicological or analytical assessment is required. The machine supplier should identify materials accurately, preserve grade traceability and provide available supplier documentation within the contracted scope.
Record the boundary in the URS: which parts require declaration, supplier statement, food-contact or pharmacopoeial evidence where relevant, extractables data, targeted leachables testing or no additional study based on documented risk. Do not convert a generic declaration into a medicinal-product approval claim.
Create a Location-Based URS Decision Matrix
Direct answer: The most useful URS matrix has one row per contact location and connects medium, exposure, duty, proposed material, evidence and acceptance owner.
Use equipment tags or drawing positions so each row can be verified during design review and FAT. Include normal product, concentrated product where credible, cleaning media, rinse, air or gas contact and lubricants that could reach the product path. Identify whether the component is permanent, single-use or routinely replaced.
For each proposal, record the source of compatibility evidence and residual risk. Status fields can be Approved, Approved with test, Pending data or Rejected. Open items should have an owner and due date before manufacturing release. This prevents late substitutions and untraceable verbal decisions.
The matrix can cover tube fillers, bottle fillers, syringe fillers and transfer systems without becoming a general equipment URS. For ointment, cream and gel packs, the KING PACK tube filling and sealing machine range is a relevant product path, while the matrix remains focused on contact materials and cleaning exposure.
| Location / medium | Exposure and duty | Proposed material | Required evidence | Decision |
|---|---|---|---|---|
| Bulk hose / product | Maximum temperature, hold time, bend and vacuum | Named liner and reinforcement | Grade data, pressure/vacuum rating and compatibility review | Owner approval |
| Meter seal / product | Dynamic cycles, pressure and cleaning | Named elastomer compound | Compound data, functional test and traceability | Approve/test |
| Nozzle / product | Intermittent contact, drip and cleaning | 316L plus named seal | Material certificate, finish evidence and seal review | Approve/open |
| Valve seat / product and CIP | Compression, switching and worst cleaning case | Named polymer/compound | Media-temperature-time review and cycle test | Approve/test |
| Transfer fitting / cleaning | Disassembly, rinse and operator handling | Specified metal and gasket | Drawing, CoC and cleaning inspection | Approve/open |
Define Material Documentation and Traceability
Direct answer: The evidence package should let the user trace each product-contact material from the approved matrix to the installed component and future spare part.
Agree the document list before order: product-contact parts list, materials of construction, controlled P&ID or flow diagram, general arrangement, material certificates or certificates of conformity, gasket and hose declarations, surface-finish report, weld records, passivation or treatment records where specified, manuals and spare-parts list.
Use consistent equipment tags, drawing item numbers and spare-part codes. If a standard purchased component contains hidden product-contact materials, request the manufacturer’s bill of materials or suitable declaration within confidentiality limits. Record exceptions and user approvals rather than labeling the entire assembly as one material.
Store the approved document revision with the equipment lifecycle records. A replacement hose or O-ring that fits mechanically can still change the validated material boundary. Purchasing descriptions should therefore include the approved manufacturer, grade or controlled equivalent and the change-notification requirement.
Control Substitutions and Spare Parts
Direct answer: No product-contact material should be substituted solely because it has the same generic family name or dimensions.
Define the supplier’s change-notification obligations for alloy source, polymer compound, hose construction, cure system, colorant, manufacturing site, surface treatment or component design. The user should assess effect on product compatibility, cleaning, extractables, wear, settings, maintenance intervals and validation status.
Classify critical spares and retain traceable certificates where needed. Set storage conditions and shelf-life controls for elastomers and hoses using the component supplier’s recommendations. Train maintenance teams to compare the full approved part number rather than diameter or color alone.
During design qualification and periodic review, reconcile the installed parts list to the approved matrix. A controlled equivalence route can reduce obsolescence risk, but it must state the technical evidence and approval process before substitution.
Inspect Product-Contact Construction During FAT
Direct answer: FAT can verify materials, installation, documentation, drainage, access and representative function; it cannot by itself prove long-term product compatibility or cleaning validation.
EU GMP Annex 15 supports risk-based qualification and validation and describes FAT/SAT as project evidence where appropriate. The user should approve protocol scope and deviations through its quality system. Long-term chemical exposure, toxicological suitability and cleaning effectiveness usually require additional site or laboratory evidence.
- Reconcile the installed product-contact parts list to approved drawings and material matrix.
- Check material certificates, gasket and hose grades, part numbers and traceability against equipment tags.
- Inspect accessible internal surfaces, welds, dead legs, gasket intrusion, drainage and cleanability against the URS.
- Verify the specified surface-finish report and measurement locations where required.
- Run representative product or justified simulant through fill, stop, restart, hold and batch-end states.
- Execute the agreed cleaning sequence to assess flow path, disassembly, drainage, rinse and operator access.
- Inspect seals and hoses after functional cycling for leakage, movement, abrasion or visible damage.
- Record deviations, substitutions, site-only tests and open SAT or qualification items before acceptance.
How to Evaluate a Veterinary Filler Supplier
Direct answer: Choose a supplier that requests product and cleaning data early, identifies every contact material and links installed parts to traceable evidence.
The KING PACK pharmaceutical and veterinary industry solutions provide application context across liquid, paste, ointment and gel processes. Project approval still depends on the owner’s formulation and cleaning review.
- Ask for a product-contact data request before accepting a final material proposal.
- Review the full contact path, including purchased pumps, valves, hoses, sensors and filters.
- Require a location-based material matrix with evidence status and open-item owners.
- Inspect drawings, certificates, finish, weld and treatment records included in the contract.
- Confirm sample testing, FAT/SAT scope, cleaning access, spares and change-notification terms.
- Verify the exact scope of CE, ISO, food-contact or pharmacopoeial evidence; do not generalize beyond the document.
How KING PACK Supports a Product-Contact Material Review
Direct answer: KING PACK can map the proposed product path and contact materials against the customer’s disclosed formula, cleaning cycle and documentation requirements before final design release.
KING PACK Machinery is a China-based manufacturer of pharmaceutical, veterinary, cosmetic and liquid filling and packaging equipment, with core solutions covering tube filling and sealing, vacuum emulsifying, liquid filling, pet spot-on filling and prefilled syringe production systems.
For a veterinary project, KING PACK can prepare a product-contact parts list covering tanks, transfer, pumps, hoses, meters, valves, nozzles, seals and format-specific components. The engineering review can record proposed materials, surface requirements, certificates, cleaning interfaces, sample tests and open user approvals.
Send the formula or controlled compatibility conclusion, product temperature and hold time, cleaning agents and concentrations, maximum cleaning temperature, required certificates, surface criteria and package samples through the KING PACK contact page. The output can be a traceable material-confirmation table instead of a one-line 316L claim.
Frequently Asked Questions
Is 316L stainless steel suitable for every veterinary formulation?
No. It is frequently specified, but suitability still depends on the formulation, cleaning chemistry, concentration, temperature, contact time, fabrication and surface condition.
Can a gasket be approved from the polymer family alone?
No. Use the actual compound or grade, supplier data, mechanical duty and exposure conditions. Compounds within one family can differ materially.
Which is better for filler seals, EPDM or FKM?
Neither is universally better. The decision depends on product and cleaning media, temperature, pressure, motion, wear, compression and the actual compound.
Should cleaning chemicals be included in the material review?
Yes. Record each agent, concentration, temperature, contact time and sequence. Cleaning can be more aggressive than production exposure.
Does a chemical-resistance chart replace testing?
No. It is a screening tool. Representative immersion, functional, toxicological or analytical work may still be required by the owner’s risk assessment.
Who is responsible for extractables and leachables?
The product owner makes the product-quality and regulatory assessment. The equipment supplier identifies materials and provides contracted supplier evidence and traceability.
What material records should be checked at FAT?
Check the contact-parts list, drawings, certificates, gasket and hose grades, surface-finish and treatment records, weld documentation where applicable, and installed spare-part identities.
Can an equivalent spare seal be used after delivery?
Only through the approved change process. Mechanical fit and a matching family name do not establish equivalent chemical, mechanical or product-quality performance.
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