Pennant Engineering Pvt. Ltd. Supplies Balanced Pressure Thermostatic Air Vent. Pennant Engineering Pvt. Ltd. Is an ISO 9001: 2000 recognised company manufacturing a wide range of steam traps, control valves, pressure reducing valves and speciality products for various industrial applications. The Balanced Pressure Thermostatic Air Vent of model number PT31AV is available with in-built strainer and screwed end connections. The Balanced Pressure Thermostatic Air Vent comes in complete stainless steel construction with capacity of 450 at PMO [kg/hr].