Vent restriction devices must not be installed in systems with which type of pumps?

Vent restriction devices are designed to control or limit the airflow to or from a system. In the context of pumps, particularly suction pumps, having a vent restriction could lead to a variety of operational issues. Suction pumps rely on the negative pressure created within the pump and system to draw liquid into the pump. If the air vent is restricted, it can create a vacuum condition, causing cavitation or insufficient fluid flow into the pump. This can lead to equipment damage, reduced efficiency, and potential system failures.

On the other hand, pressure pumps, submersible pumps, and air eliminators can typically accommodate venting systems without the same degree of detrimental effects. Pressure pumps manage fluid flow through positive pressure, and submersible pumps operate in a submerged environment where venting is less critical. Air eliminators are designed to release trapped air without impacting the overall operation of a fluid system.

Understanding these details is key for ensuring the correct installation and operation of different pump types and managing their interacting systems effectively. Therefore, the correct answer highlights the critical nature of venting requirements in relation to suction pumps specifically.