When choosing a PE pipe fitting mould, consider the following factors:

1. Size: Choose a mould that produces fittings that are the correct size for your piping system. Look for a mould that can produce a range of sizes, if necessary.

2. Material: Choose a mould made from high-quality materials that are durable and can withstand the pressure and heat of the molding process. Look for a mould made from high-grade steel or aluminum.

3. Design: Choose a mould with a design that produces the desired shape and features of your pipe fittings. Look for a mould with a design that is optimized for high efficiency and consistent quality.
   

4. Cavities: Consider the number of cavities in the mould. A mould with multiple cavities can produce more fittings in a shorter amount of time, which can increase productivity.

5. Brand and Reputation: Choose a mould from a reputable manufacturer that has a proven track record of producing high-quality molds. Look for a manufacturer that offers good customer service and technical support.

6. Price: PE pipe fitting moulds can range in price from a few hundred to several thousand dollars. Consider your budget and choose a mould that fits within your price range.

7. Customization: Consider whether you need a customized mould for specific features or designs. Some manufacturers offer customized molds for specific requirements.

By considering these factors, you can choose a PE pipe fitting mould that is effective, durable, and meets your specific requirements.