# Valve bags > Block-bottom PP woven valve bags for 25–50 kg cement, mortar, putty, chemicals and flour. Inner or outer valves, laminated or coated fabric, heat-sealed or sewn, custom printed. Valve bags are filled through a small sleeve in one corner and close themselves under the product's own pressure, so high-speed packers can fill them without sewing. Our square block-bottom construction stacks like a brick on the pallet and stays dust-tight in transit. ## Specification guide | Item | Detail | |---|---| | Fill weight | Typically 20, 25, 40 and 50 kg; other sizes to order. | | Valve type | Internal valve, external (extended) valve or heat-sealable valve sleeve. | | Fabric | PP woven 70–150 g/m², PE-coated or BOPP-laminated for moisture resistance; two-layer and kraft-paper options. | | Closure | Self-closing valve, ultrasonic or heat seal, adhesive bottom. | ## Products - [25kg Moisture Proof PP Valve Bag with Self Adhesive Seal and Screen Printing for Packing Powder Waterproof](https://www.egpbags.com/products/valve-bags/25kg-moisture-proof-pp-valve-bag-with-self-adhesive-seal-and-screen/) - [Heavy Duty Bottom Gusset Bag Valve Pocket 25KG Capacity Moisture-proof Waterproof PP Agricultural Chemical Packaging](https://www.egpbags.com/products/valve-bags/heavy-duty-bottom-gusset-bag-valve-pocket-25kg-capacity-moisture/) - [Custom Logo Square Bottom Laminated PP Woven Waterproof Cement Packing Bags Valve 25kg Capacity OEM Factory Low Price](https://www.egpbags.com/products/valve-bags/custom-logo-square-bottom-laminated-pp-woven-waterproof-cement/) - [Square Bottom Gusset Bag with Valve Pocket Durable 25KG Chemical Raw Material Packaging Waterproof OEM Factory](https://www.egpbags.com/products/valve-bags/square-bottom-gusset-bag-with-valve-pocket-durable-25kg-chemical-raw/) - [Heavy Duty Bottom Gusset Bag Valve Pocket 25KG Capacity Moisture-proof Black PP Customizable Agricultural Flour Fertilizer](https://www.egpbags.com/products/valve-bags/heavy-duty-bottom-gusset-bag-valve-pocket-25kg-capacity-moisture-2/) - [Bottom Gusset Bag with Valve Pocket PP Woven Fabric 25KG Flour Fertilizer Feed Packaging Moisture-proof Waterproof](https://www.egpbags.com/products/valve-bags/bottom-gusset-bag-with-valve-pocket-pp-woven-fabric-25kg-flour/) - [Heavy Duty Bottom Gusset Bag Valve Pocket 25KG Capacity Waterproof PP Agricultural Chemical Packaging Custom](https://www.egpbags.com/products/valve-bags/heavy-duty-bottom-gusset-bag-valve-pocket-25kg-capacity-waterproof-pp/) - [Heavy Duty Heat Seal Bottom Gusset Bag Valve Pocket 25KG Capacity Moisture-proof PP Agricultural Chemical Packaging](https://www.egpbags.com/products/valve-bags/heavy-duty-heat-seal-bottom-gusset-bag-valve-pocket-25kg-capacity/) - [Heavy Duty Bottom Gusset PP Waterproof Agricultural Chemical Packaging Bag Valve 25KG Capacity for Flour Feed](https://www.egpbags.com/products/valve-bags/heavy-duty-bottom-gusset-pp-waterproof-agricultural-chemical/) - [Custom-made Durable Two Layer LDPE Valve Bags Custom Logo Pad/Silk Screen Printing 25kg Powder Resin Fertilizer Agriculture Feed](https://www.egpbags.com/products/valve-bags/custom-made-durable-two-layer-ldpe-valve-bags-custom-logo-pad-silk/) - [Heavy Duty Bottom Gusset PP Agricultural Chemical Packaging Bag with Valve 25KG Capacity](https://www.egpbags.com/products/valve-bags/heavy-duty-bottom-gusset-pp-agricultural-chemical-packaging-bag-with/) - [Heavy Duty Square PP Agricultural Chemical Packaging Bag with Valve 25KG Capacity Moisture Proof Fertilizer & Feed](https://www.egpbags.com/products/valve-bags/heavy-duty-square-pp-agricultural-chemical-packaging-bag-with-valve/) - [Custom-made Two Layer PP Waterproof Valve Bags with Heat Seal for 25kg Flour Feed Fertilizer or Resin Packing](https://www.egpbags.com/products/valve-bags/custom-made-two-layer-pp-waterproof-valve-bags-with-heat-seal-for/) - [Heavy Duty PP Woven Fabric Waterproof Agricultural Chemical Packaging Bag Valve 25KG Plastics](https://www.egpbags.com/products/valve-bags/heavy-duty-pp-woven-fabric-waterproof-agricultural-chemical-packaging/) - [Custom-made Two Layer PP Woven Moisture Proof Waterproof Valve Bags for 25kg Agriculture Fertilizer Flour Feed Powder Resin](https://www.egpbags.com/products/valve-bags/custom-made-two-layer-pp-woven-moisture-proof-waterproof-valve-bags/) - [Food Grade Bottom Gusset PP Agricultural Chemical Resealable Packaging Bag with Valve 25KG Capacity](https://www.egpbags.com/products/valve-bags/food-grade-bottom-gusset-pp-agricultural-chemical-resealable/) ## FAQ ### What is the difference between an inner and outer valve? An inner valve tucks inside the bag and is closed by product pressure: simple and economical. An outer (extended) valve protrudes slightly so it can be folded or heat-sealed after filling, giving better dust control for fine powders such as cement, gypsum or titanium dioxide. ### Are your valve bags suitable for automatic packing machines? Yes. Block-bottom valve bags are designed for rotary and inline valve packers. Send us your packer model and spout diameter and we will match the valve width and bag dimensions. ### Can valve bags be printed? Yes. Gravure print on BOPP lamination for photographic graphics, or screen and offset print on coated fabric for simpler designs. ### What bag is used for cement? Most cement is packed in self-closing valve bags — either multiwall paper or laminated PP woven — filled on rotary or inline valve packers. See our cement bag guide. ### How much does a bag of cement weigh? Portland cement is sold in 94 lb sacks in the US and 25, 40 or 50 kg bags elsewhere; premixed concrete commonly comes in 40, 50, 60, 80 and 90 lb bags. Contact: doristeng2013@yt-evergreen.com · +86 186 6389 6305