Kalrez 4079 vs Markez Z1: FFKM Compound Comparison

Home › Guides › Kalrez 4079 vs Markez Z1: FFKM Compound Comparison

Reviewed by MLC Editorial Team | 7 June 2026

Top view of a minimalist chemistry experiment with two petri dishes on a white background. — Photo by Ron Lach on Pexels

Kalrez 4079 and Markez Z1 are both perfluoroelastomer (FFKM) compounds used in chemical, refinery, and process applications. Kalrez 4079 vs Markez Z1 They share similar chemistry but differ on temperature ceiling, hardness, and intended service. This page compares the two side-by-side and explains when to specify each.

Side-by-side comparison

Property	Kalrez 4079	Markez Z1
Manufacturer	DuPont (Chemours)	Marco Rubber
Compound	4079	Z1
Maximum continuous temp	316°C	327°C
Minimum temp	0°C	-25°C
Hardness	75 Shore A	75 Shore A
Colour	Black	Black
Typical applications	Steam, hot amines, ethylene oxide, sour gas, refinery valves, pulp and paper digesters	Chemical process, refinery

When to specify Kalrez 4079

Kalrez 4079 suits steam and similar service. Continuous temperature window is 0°C to 316°C, hardness 75 Shore A. Manufactured by DuPont (Chemours).

Limitation: Not recommended for fully fluorinated solvents; cost.

When to specify Markez Z1

Markez Z1 suits chemical process and similar service. Continuous temperature window is -25°C to 327°C, hardness 75 Shore A. Manufactured by Marco Rubber.

Key differences

Temperature ceiling: Markez Z1 runs 11°C hotter (327°C vs 316°C). Specify the higher-rated compound when continuous service is above 316°C.
Hardness: Both are 75 Shore A, so groove design and squeeze percentage are interchangeable.
Manufacturer: Kalrez 4079 is from DuPont (Chemours); Markez Z1 is from Marco Rubber. Lead time and UK availability vary by brand.
Cost: FFKM pricing varies by manufacturer, batch size, and stock position. Both compounds are at the premium end of elastomer pricing (£30 to £500+ per O-ring depending on size).

Get a UK quote on either compound

Get a quote for Kalrez 4079 vs Markez Z1: FFKM Compound Comparison

Acumen Seals & Pumps - UK specialist in mechanical seals, FFKM O-rings, Kalrez compounds, and elastomer parts. 36 years of inventory, UK stock with 24-48 hour despatch, and a price back within 4 working hours.

Send an enquiry via the MLC contact form

Related pages

References

Frequently Asked Questions

Can I substitute Kalrez 4079 for Markez Z1?

Yes, Kalrez 4079 and Markez Z1 are both FFKM compounds with overlapping chemical compatibility. Verify your specific fluid against both manufacturers' compatibility tables before substitution. Temperature window, hardness, and certifications may differ.

Which is hotter: Kalrez 4079 or Markez Z1?

Markez Z1 has a higher continuous temperature ceiling (327°C vs 316°C, a 11°C difference).

Which costs less: Kalrez 4079 or Markez Z1?

FFKM compound pricing depends on manufacturer, batch size, certifications, and current stock position rather than headline brand. Both compounds are at the premium end of elastomer pricing. Get current UK quotes on both before specifying.

Where can I buy Kalrez 4079 or Markez Z1 in the UK?

Both compounds are supplied in the UK by independent FFKM seal specialists carrying multiple manufacturer lines. Lead time is typically 2-5 working days for stock BS 1806 / AS568 sizes, 4-8 weeks for custom-moulded sizes.

Independent UK engineering trade publication. Company profiles cross-referenced with Companies House.

© 2026 My Local Components. All rights reserved.

(function(){ window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} window.gtag = gtag; gtag('js', new Date()); gtag('config', 'G-1E26RMVJ59', { page_path: location.pathname + location.search }); // Lead-action tracking: hook into supplier outbound-website / call / email links. // POSTs to /api/track which writes to lead_actions table. function getPageContext() { var path = location.pathname.replace(/\/$/, ''); var m = path.match(/^\/(suppliers|products|areas|guides|standards|trade-bodies|news|brands|glossary)\/([a-z0-9-]+)/); if (!m) return null; var typeMap = { suppliers:'suppliers', products:'product_categories', areas:'areas', guides:'guides', standards:'standards', 'trade-bodies':'trade_bodies', news:'news_articles', brands:'brands', glossary:'glossary_terms' }; return { page_type: typeMap[m[1]] || m[1], page_slug: m[2] }; } function trackClick(action) { var ctx = getPageContext(); if (!ctx) return; var body = JSON.stringify({ action: action, page_type: ctx.page_type, page_slug: ctx.page_slug, page_name: document.title || '' }); try { navigator.sendBeacon('/api/track', new Blob([body], { type:'application/json' })); } catch(e){ fetch('/api/track', { method:'POST', headers:{'Content-Type':'application/json'}, body: body, keepalive: true }); } } document.addEventListener('click', function(ev){ var a = ev.target.closest && ev.target.closest('a'); if (!a) return; var href = a.getAttribute('href') || ''; if (href.startsWith('tel:')) return trackClick('call_phone'); if (href.startsWith('mailto:')) return trackClick('visit_website'); // External outbound link to a supplier - wrapAffiliate already adds // rel="...sponsored" + target="_blank" + data-affiliate-domain. var host = ''; try { host = new URL(href, location.origin).hostname.replace(/^www\./,''); } catch(e){} if (host && host !== location.hostname.replace(/^www\./,'')) { trackClick('visit_website'); } }, { passive: true }); })();

Get a UK price for Kalrez 4079 vs Markez Z1: FFKM Compound Comparison

Andrew Sykes at Acumen Seals & Pumps — 36 years in sealing. UK stock with 24–48 hour despatch, and a price back within 4 working hours. OEM and production-run enquiries welcome, from a single seal to scheduled supply of thousands of parts.

Your enquiry goes straight to Acumen Seals & Pumps in the UK. No obligation, and we never pass your details to anyone else.