In China there are many other pump and mechanical seal manufacturers allow standard pumps to be operated at temperature up to 150℃ when there is not any cooling system to shaft seals. However, deformation of the seal surfaces, high thermal stresses and friction of shaft seals may lead to a pump short service life and higher maintenance cost. Therefore, to use expensive cooling system for pump is required when operation temperature is more than 150℃.This is not happening to SMC NL series internal gear pump, where the mechanical seal is placed at the motor drive end of pump, by means of a heat barrier, a favorable temperature drop is achieved without any cooled system. Even the gear pump inlet temperature is up to 300℃,there is not any problem for pump to operate safely because in the seal area temperature will not exceed 100℃. In July 2024 we exported such gear pump to Malaysia for 250℃ hot oil, this gear pump capacity is 6.28m3/h at 5.3bar, shaft power is 1.8kw only.