You will need to use your Promo Codes at Airliquide by following these steps: You need to log in to your existing account at airliquide.com or create a new account of your own; then, to select a product, you can browse the airliquide.com product page to select a product and add it to your cart. Occasionally, they will offer you discounted products up to 45%. Next, click on [Proceed to Payment], below the items listed, you will see a box that says [Add Coupon Codes]; tick the Airliquide Coupons of your choice and automatically return to the checkout page, You will see that the actual payment total has been reduced.