1. Material Selection  

Brass

     - Advantages: Brass angle valves are an ideal choice. They are easy to process, highly malleable, and offer excellent hardness, resistance to bending and torsion, and durability. Brass also provides strong corrosion resistance, preventing rust and ensuring long-term use without contaminating water quality. For example, premium brass angle valves from reputable brands can last over 10 years.  

     - Identification: High-quality brass valves have a uniform golden-yellow color, smooth surfaces, and no visible flaws. They feel heavier compared to other materials.  

Stainless Steel

     Stainless steel angle valves offer good mechanical strength and corrosion resistance. However, they are slightly harder to process than brass and may lack refinement in certain details. Suitable for scenarios requiring high corrosion resistance, though they may be pricier.  

Alloy

     Alloy angle valves are cost-effective but have lower resistance to bending/torsion and are prone to oxidation, leading to shorter lifespans. Issues like Cartridge wear and leaks may occur, making them unsuitable for long-term use.  

Plastic

     Lightweight and affordable, plastic valves are easy to install. However, they have poor heat and corrosion resistance, making them unfit for high-temperature or corrosive environments. In cold climates, plastic may become brittle and fail.  

2. Cartridge  

Ceramic Cartridge

     The mainstream choice for households. Offers smooth operation, durability, and excellent leak-proof performance. High-quality ceramic cartridges maintain integrity even after repeated use.  

Ball Cartridge

     Features a larger diameter to maintain water pressure and flow, ideal for high-demand appliances like water heaters. Operates with a simple 90-degree rotation.  

ABS (Engineering Plastic) Cartridge

     Low-cost but prone to wear, aging, and leaks. Not recommended.  

Rubber Rotary Cartridge

     Outdated design, difficult to operate, and poor sealing. Rarely used in modern households.  

3. Electroplating Finish  

   High-quality angle valves have a mirror-like finish under light, free of oxidation spots, burn marks, pores, bubbles, or uneven coating. Smooth surfaces should feel flawless to the touch. A fingerprint test (quick dispersion and minimal water scale residue) indicates superior electroplating. Poor plating leads to rust and corrosion.  

4. Hot/Cold Differentiation  

   Angle valves are typically labeled "Cold" (blue) or "Hot" (red). Most high-end valves with heat-resistant cores (e.g., ceramic) are universal, but installing separate valves for hot and cold water is recommended for clarity. Low-end valves with rubber cores must differentiate due to material limitations.  

5. Opening Mechanism  

Quick-Open:  

     90-degree rotation for instant on/off operation. Modern standard for convenience.  

Slow-Open:  

     Requires 360-degree rotation. Obsolete and cumbersome.  

6. Brand Reputation  

   Opt for reputable brands for assured quality and after-sales support. Established brands adhere to strict manufacturing standards.  

7. Size Compatibility  

   - 3/8" (3分): Fits 3/8" pipes, commonly used for faucet inlets.  

   - 1/2" (4分): Fits 1/2" pipes, standard for sinks, toilets, water heaters, and showers. Most common household size.  

   - 3/4" (6分): Fits 3/4" pipes, typically used for main water lines or large appliances. Rarely needed for standard home setups.